Alien-FreeImage
view release on metacpan or search on metacpan
src/Source/FreeImage/PluginDDS.cpp view on Meta::CPAN
}
#endif
// ==========================================================
// Get the 4 possible colors for a block
//
static void
GetBlockColors (const DXTColBlock &block, Color8888 colors[4], bool isDXT1) {
int i;
// expand from 565 to 888
for (i = 0; i < 2; i++) {
colors[i].a = 0xff;
/*
colors[i].r = (BYTE)(block.colors[i].r * 0xff / 0x1f);
colors[i].g = (BYTE)(block.colors[i].g * 0xff / 0x3f);
colors[i].b = (BYTE)(block.colors[i].b * 0xff / 0x1f);
*/
colors[i].r = (BYTE)((block.colors[i].r << 3U) | (block.colors[i].r >> 2U));
colors[i].g = (BYTE)((block.colors[i].g << 2U) | (block.colors[i].g >> 4U));
colors[i].b = (BYTE)((block.colors[i].b << 3U) | (block.colors[i].b >> 2U));
src/Source/FreeImage/PluginPICT.cpp view on Meta::CPAN
WORD len = Read16( io, handle ) - 2;
io->seek_proc(handle, len, SEEK_CUR);
}
/**
Width in bytes for 8 bpp or less.
Width in pixels for 16 bpp.
Expands Width units to 32-bit pixel data.
*/
static void
expandBuf( FreeImageIO *io, fi_handle handle, int width, int bpp, BYTE* dst ) {
switch (bpp) {
case 16:
for ( int i=0; i<width; i++) {
WORD src = Read16( io, handle );
dst[ FI_RGBA_BLUE ] = (src & 31)*8; // Blue
dst[ FI_RGBA_GREEN ] = ((src >> 5) & 31)*8; // Green
dst[ FI_RGBA_RED ] = ((src >> 10) & 31)*8; // Red
dst[ FI_RGBA_ALPHA ] = 0xFF; // Alpha
dst += 4;
}
break;
default:
throw "Bad bits per pixel in expandBuf.";
}
}
/**
Expands Width units to 8-bit pixel data.
Max. 8 bpp source format.
*/
static void
expandBuf8( FreeImageIO *io, fi_handle handle, int width, int bpp, BYTE* dst )
{
switch (bpp) {
case 8:
io->read_proc( dst, width, 1, handle );
break;
case 4:
for (int i = 0; i < width; i++) {
WORD src = Read8( io, handle );
*dst = (src >> 4) & 15;
*(dst+1) = (src & 15);
src/Source/FreeImage/PluginPICT.cpp view on Meta::CPAN
}
if (width & 7) { // Check for leftover pixels
for (int i = 7; i > (8-width & 7); i--) {
WORD src = Read8( io, handle );
*dst = (src >> i) & 1;
dst++;
}
}
break;
default:
throw "Bad bits per pixel in expandBuf8.";
}
}
static BYTE*
UnpackPictRow( FreeImageIO *io, fi_handle handle, BYTE* pLineBuf, int width, int rowBytes, int srcBytes ) {
if (rowBytes < 8) { // Ah-ha! The bits aren't actually packed. This will be easy.
io->read_proc( pLineBuf, rowBytes, 1, handle );
}
else {
src/Source/FreeImage/PluginPICT.cpp view on Meta::CPAN
default:
sprintf( outputMessage, "Illegal bpp value in unpackbits: %d\n", pixelSize );
throw outputMessage;
}
if (rowBytes < 8) {
// ah-ha! The bits aren't actually packed. This will be easy.
for ( int i = 0; i < height; i++ ) {
BYTE* dst = (BYTE*)FreeImage_GetScanLine( dib, height - 1 - i);
if (pixelSize == 16) {
expandBuf( io, handle, width, pixelSize, dst );
} else {
expandBuf8( io, handle, width, pixelSize, dst );
}
}
}
else {
for ( int i = 0; i < height; i++ ) {
// For each line do...
int linelen; // length of source line in bytes.
if (rowBytes > 250) {
linelen = Read16( io, handle );
} else {
src/Source/FreeImage/PluginPICT.cpp view on Meta::CPAN
// Special case: repeat value of 0.
// Apple says ignore.
j++;
}
else {
// Packed data.
int len = ((FlagCounter ^ 255) & 255) + 2;
// This is slow for some formats...
if (pixelSize == 16) {
expandBuf( io, handle, 1, pixelSize, dst );
for ( int k = 1; k < len; k++ ) {
// Repeat the pixel len times.
memcpy( dst+(k*4*PixelPerRLEUnit), dst, 4*PixelPerRLEUnit);
}
dst += len*4*PixelPerRLEUnit;
}
else {
expandBuf8( io, handle, 1, pixelSize, dst );
for ( int k = 1; k < len; k++ ) {
// Repeat the expanded byte len times.
memcpy( dst+(k*PixelPerRLEUnit), dst, PixelPerRLEUnit);
}
dst += len*PixelPerRLEUnit;
}
j += pkpixsize + 1;
}
}
else {
// Unpacked data
int len = (FlagCounter & 255) + 1;
if (pixelSize == 16) {
expandBuf( io, handle, len, pixelSize, dst );
dst += len*4*PixelPerRLEUnit;
}
else {
expandBuf8( io, handle, len, pixelSize, dst );
dst += len*PixelPerRLEUnit;
}
j += ( len * pkpixsize ) + 1;
}
}
}
}
}
}
src/Source/FreeImage/PluginPNG.cpp view on Meta::CPAN
// check allowed combinations of colour type and bit depth
// then get converted FreeImage type
switch(color_type) {
case PNG_COLOR_TYPE_GRAY: // color type '0', bitdepth = 1, 2, 4, 8, 16
switch(bit_depth) {
case 1:
case 2:
case 4:
case 8:
// expand grayscale images to the full 8-bit from 2-bit/pixel
if (pixel_depth == 2) {
png_set_expand_gray_1_2_4_to_8(png_ptr);
}
// if a tRNS chunk is provided, we must also expand the grayscale data to 8-bits,
// this allows us to make use of the transparency table with existing FreeImage methods
if (bIsTransparent && (pixel_depth < 8)) {
png_set_expand_gray_1_2_4_to_8(png_ptr);
}
break;
case 16:
image_type = (pixel_depth == 16) ? FIT_UINT16 : FIT_UNKNOWN;
// 16-bit grayscale images can contain a transparent value (shade)
// if found, expand the transparent value to a full alpha channel
if (bIsTransparent && (image_type != FIT_UNKNOWN)) {
// expand tRNS to a full alpha channel
png_set_tRNS_to_alpha(png_ptr);
// expand new 16-bit gray + 16-bit alpha to full 64-bit RGBA
png_set_gray_to_rgb(png_ptr);
image_type = FIT_RGBA16;
}
break;
default:
image_type = FIT_UNKNOWN;
break;
}
src/Source/FreeImage/PluginPNG.cpp view on Meta::CPAN
break;
default:
image_type = FIT_UNKNOWN;
break;
}
// sometimes, 24- or 48-bit images may contain transparency information
// check for this use case and convert to an alpha-compatible format
if (bIsTransparent && (image_type != FIT_UNKNOWN)) {
// if the image is 24-bit RGB, mark it as 32-bit; if it is 48-bit, mark it as 64-bit
image_type = (pixel_depth == 24) ? FIT_BITMAP : (pixel_depth == 48) ? FIT_RGBA16 : FIT_UNKNOWN;
// expand tRNS chunk to alpha channel
png_set_tRNS_to_alpha(png_ptr);
}
break;
case PNG_COLOR_TYPE_PALETTE: // color type '3', bitdepth = 1, 2, 4, 8
switch(bit_depth) {
case 1:
case 2:
case 4:
case 8:
// expand palette images to the full 8 bits from 2 bits/pixel
if (pixel_depth == 2) {
png_set_packing(png_ptr);
}
// if a tRNS chunk is provided, we must also expand the palletized data to 8-bits,
// this allows us to make use of the transparency table with existing FreeImage methods
if (bIsTransparent && (pixel_depth < 8)) {
png_set_packing(png_ptr);
}
break;
default:
image_type = FIT_UNKNOWN;
break;
}
src/Source/FreeImage/PluginPNG.cpp view on Meta::CPAN
image_type = (pixel_depth == 16) ? FIT_BITMAP : FIT_UNKNOWN;
break;
case 16:
// 16-bit grayscale + 16-bit alpha => convert to 64-bit RGBA
image_type = (pixel_depth == 32) ? FIT_RGBA16 : FIT_UNKNOWN;
break;
default:
image_type = FIT_UNKNOWN;
break;
}
// expand 8-bit greyscale + 8-bit alpha to 32-bit
// expand 16-bit greyscale + 16-bit alpha to 64-bit
png_set_gray_to_rgb(png_ptr);
break;
case PNG_COLOR_TYPE_RGB_ALPHA: // color type '6', bitdepth = 8, 16
switch(bit_depth) {
case 8:
break;
case 16:
image_type = (pixel_depth == 64) ? FIT_RGBA16 : FIT_UNKNOWN;
break;
src/Source/LibJPEG/cdjpeg.h view on Meta::CPAN
*/
JSAMPARRAY buffer;
JDIMENSION buffer_height;
};
/*
* cjpeg/djpeg may need to perform extra passes to convert to or from
* the source/destination file format. The JPEG library does not know
* about these passes, but we'd like them to be counted by the progress
* monitor. We use an expanded progress monitor object to hold the
* additional pass count.
*/
struct cdjpeg_progress_mgr {
struct jpeg_progress_mgr pub; /* fields known to JPEG library */
int completed_extra_passes; /* extra passes completed */
int total_extra_passes; /* total extra */
/* last printed percentage stored here to avoid multiple printouts */
int percent_done;
};
src/Source/LibJPEG/coderules.txt view on Meta::CPAN
declarations: the function name MUST BEGIN IN COLUMN 1. Thus all functions
should be written in the following style:
LOCAL(int *)
function_name (int a, char *b)
{
code...
}
Note that each function definition must begin with GLOBAL(type), LOCAL(type),
or METHODDEF(type). These macros expand to "static type" or just "type" as
appropriate. They provide a readable indication of the routine's usage and
can readily be changed for special needs. (For instance, special linkage
keywords can be inserted for use in Windows DLLs.)
ansi2knr does not transform method declarations (function pointers in
structs). We handle these with a macro JMETHOD, defined as
#ifdef HAVE_PROTOTYPES
#define JMETHOD(type,methodname,arglist) type (*methodname) arglist
#else
#define JMETHOD(type,methodname,arglist) type (*methodname) ()
src/Source/LibJPEG/filelist.txt view on Meta::CPAN
jutils.c Miscellaneous utility routines.
jmemmgr.c relies on a system-dependent memory management module. The IJG
distribution includes the following implementations of the system-dependent
module:
jmemnobs.c "No backing store": assumes adequate virtual memory exists.
jmemansi.c Makes temporary files with ANSI-standard routine tmpfile().
jmemname.c Makes temporary files with program-generated file names.
jmemdos.c Custom implementation for MS-DOS (16-bit environment only):
can use extended and expanded memory as well as temp files.
jmemmac.c Custom implementation for Apple Macintosh.
Exactly one of the system-dependent modules should be configured into an
installed JPEG library (see install.txt for hints about which one to use).
On unusual systems you may find it worthwhile to make a special
system-dependent memory manager.
Non-C source code files:
src/Source/LibJPEG/install.txt view on Meta::CPAN
DEFAULT_MAX_MEM to jconfig.h, or by adding a -D switch to the Makefile).
This value limits the amount of data space the program will attempt to
allocate. Code and static data space isn't counted, so the actual memory
needs for cjpeg or djpeg are typically 100 to 150Kb more than the max-memory
setting. Larger max-memory settings reduce the amount of I/O needed to
process a large image, but too large a value can result in "insufficient
memory" failures. On most Unix machines (and other systems with virtual
memory), just set DEFAULT_MAX_MEM to several million and forget it. At the
other end of the spectrum, for MS-DOS machines you probably can't go much
above 300K to 400K. (On MS-DOS the value refers to conventional memory only.
Extended/expanded memory is handled separately by jmemdos.c.)
BUILDING THE SOFTWARE
=====================
Now you should be able to compile the software. Just say "make" (or
whatever's necessary to start the compilation). Have a cup of coffee.
Here are some things that could go wrong:
src/Source/LibJPEG/install.txt view on Meta::CPAN
Note that this makefile assumes that the working copy of itself is called
"makefile". If you want to call it something else, say "makefile.mak",
be sure to adjust the dependency line that reads "$(RFILE) : makefile".
Otherwise the make will fail because it doesn't know how to create "makefile".
Worse, some releases of Microsoft's make utilities give an incorrect error
message in this situation.
Old versions of MS C fail with an "out of macro expansion space" error
because they can't cope with the macro TRACEMS8 (defined in jerror.h).
If this happens to you, the easiest solution is to change TRACEMS8 to
expand to nothing. You'll lose the ability to dump out JPEG coefficient
tables with djpeg -debug -debug, but at least you can compile.
Original MS C 6.0 is very buggy; it compiles incorrect code unless you turn
off optimization entirely (remove -O from CFLAGS). 6.00A is better, but it
still generates bad code if you enable loop optimizations (-Ol or -Ox).
MS C 8.0 crashes when compiling jquant1.c with optimization switch /Oo ...
which is on by default. To work around this bug, compile that one file
with /Oo-.
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
#endif
}
/*
* Expand an image vertically from height input_rows to height output_rows,
* by duplicating the bottom row.
*/
LOCAL(void)
expand_bottom_edge (JSAMPARRAY image_data, JDIMENSION num_cols,
int input_rows, int output_rows)
{
register int row;
for (row = input_rows; row < output_rows; row++) {
jcopy_sample_rows(image_data, input_rows-1, image_data, row,
1, num_cols);
}
}
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
prep->color_buf,
(JDIMENSION) prep->next_buf_row,
numrows);
*in_row_ctr += numrows;
prep->next_buf_row += numrows;
prep->rows_to_go -= numrows;
/* If at bottom of image, pad to fill the conversion buffer. */
if (prep->rows_to_go == 0 &&
prep->next_buf_row < cinfo->max_v_samp_factor) {
for (ci = 0; ci < cinfo->num_components; ci++) {
expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
prep->next_buf_row, cinfo->max_v_samp_factor);
}
prep->next_buf_row = cinfo->max_v_samp_factor;
}
/* If we've filled the conversion buffer, empty it. */
if (prep->next_buf_row == cinfo->max_v_samp_factor) {
(*cinfo->downsample->downsample) (cinfo,
prep->color_buf, (JDIMENSION) 0,
output_buf, *out_row_group_ctr);
prep->next_buf_row = 0;
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
}
/* If at bottom of image, pad the output to a full iMCU height.
* Note we assume the caller is providing a one-iMCU-height output buffer!
*/
if (prep->rows_to_go == 0 &&
*out_row_group_ctr < out_row_groups_avail) {
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
numrows = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size;
expand_bottom_edge(output_buf[ci],
compptr->width_in_blocks * compptr->DCT_h_scaled_size,
(int) (*out_row_group_ctr * numrows),
(int) (out_row_groups_avail * numrows));
}
*out_row_group_ctr = out_row_groups_avail;
break; /* can exit outer loop without test */
}
}
}
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
*in_row_ctr += numrows;
prep->next_buf_row += numrows;
prep->rows_to_go -= numrows;
} else {
/* Return for more data, unless we are at the bottom of the image. */
if (prep->rows_to_go != 0)
break;
/* When at bottom of image, pad to fill the conversion buffer. */
if (prep->next_buf_row < prep->next_buf_stop) {
for (ci = 0; ci < cinfo->num_components; ci++) {
expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
prep->next_buf_row, prep->next_buf_stop);
}
prep->next_buf_row = prep->next_buf_stop;
}
}
/* If we've gotten enough data, downsample a row group. */
if (prep->next_buf_row == prep->next_buf_stop) {
(*cinfo->downsample->downsample) (cinfo,
prep->color_buf,
(JDIMENSION) prep->this_row_group,
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
* we need five row groups' worth of pointers for each component.
*/
fake_buffer = (JSAMPARRAY)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(cinfo->num_components * 5 * rgroup_height) *
SIZEOF(JSAMPROW));
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Allocate the actual buffer space (3 row groups) for this component.
* We make the buffer wide enough to allow the downsampler to edge-expand
* horizontally within the buffer, if it so chooses.
*/
true_buffer = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) (((long) compptr->width_in_blocks *
cinfo->min_DCT_h_scaled_size *
cinfo->max_h_samp_factor) / compptr->h_samp_factor),
(JDIMENSION) (3 * rgroup_height));
/* Copy true buffer row pointers into the middle of the fake row array */
MEMCOPY(fake_buffer + rgroup_height, true_buffer,
src/Source/LibJPEG/jcprepct.c view on Meta::CPAN
if (need_full_buffer) /* safety check */
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
prep = (my_prep_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_prep_controller));
cinfo->prep = (struct jpeg_c_prep_controller *) prep;
prep->pub.start_pass = start_pass_prep;
/* Allocate the color conversion buffer.
* We make the buffer wide enough to allow the downsampler to edge-expand
* horizontally within the buffer, if it so chooses.
*/
if (cinfo->downsample->need_context_rows) {
/* Set up to provide context rows */
#ifdef CONTEXT_ROWS_SUPPORTED
prep->pub.pre_process_data = pre_process_context;
create_context_buffer(cinfo);
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
/* Downsampling method pointers, one per component */
downsample1_ptr methods[MAX_COMPONENTS];
/* Height of an output row group for each component. */
int rowgroup_height[MAX_COMPONENTS];
/* These arrays save pixel expansion factors so that int_downsample need not
* recompute them each time. They are unused for other downsampling methods.
*/
UINT8 h_expand[MAX_COMPONENTS];
UINT8 v_expand[MAX_COMPONENTS];
} my_downsampler;
typedef my_downsampler * my_downsample_ptr;
/*
* Initialize for a downsampling pass.
*/
METHODDEF(void)
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
/* no work for now */
}
/*
* Expand a component horizontally from width input_cols to width output_cols,
* by duplicating the rightmost samples.
*/
LOCAL(void)
expand_right_edge (JSAMPARRAY image_data, int num_rows,
JDIMENSION input_cols, JDIMENSION output_cols)
{
register JSAMPROW ptr;
register JSAMPLE pixval;
register int count;
int row;
int numcols = (int) (output_cols - input_cols);
if (numcols > 0) {
for (row = 0; row < num_rows; row++) {
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
* One row group is processed per call.
* This version handles arbitrary integral sampling ratios, without smoothing.
* Note that this version is not actually used for customary sampling ratios.
*/
METHODDEF(void)
int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY output_data)
{
my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample;
int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */
JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size;
JSAMPROW inptr, outptr;
INT32 outvalue;
h_expand = downsample->h_expand[compptr->component_index];
v_expand = downsample->v_expand[compptr->component_index];
numpix = h_expand * v_expand;
numpix2 = numpix/2;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
* efficient.
*/
expand_right_edge(input_data, cinfo->max_v_samp_factor,
cinfo->image_width, output_cols * h_expand);
inrow = outrow = 0;
while (inrow < cinfo->max_v_samp_factor) {
outptr = output_data[outrow];
for (outcol = 0, outcol_h = 0; outcol < output_cols;
outcol++, outcol_h += h_expand) {
outvalue = 0;
for (v = 0; v < v_expand; v++) {
inptr = input_data[inrow+v] + outcol_h;
for (h = 0; h < h_expand; h++) {
outvalue += (INT32) GETJSAMPLE(*inptr++);
}
}
*outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix);
}
inrow += v_expand;
outrow++;
}
}
/*
* Downsample pixel values of a single component.
* This version handles the special case of a full-size component,
* without smoothing.
*/
METHODDEF(void)
fullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY output_data)
{
/* Copy the data */
jcopy_sample_rows(input_data, 0, output_data, 0,
cinfo->max_v_samp_factor, cinfo->image_width);
/* Edge-expand */
expand_right_edge(output_data, cinfo->max_v_samp_factor, cinfo->image_width,
compptr->width_in_blocks * compptr->DCT_h_scaled_size);
}
/*
* Downsample pixel values of a single component.
* This version handles the common case of 2:1 horizontal and 1:1 vertical,
* without smoothing.
*
* A note about the "bias" calculations: when rounding fractional values to
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
int inrow;
JDIMENSION outcol;
JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size;
register JSAMPROW inptr, outptr;
register int bias;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
* efficient.
*/
expand_right_edge(input_data, cinfo->max_v_samp_factor,
cinfo->image_width, output_cols * 2);
for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
outptr = output_data[inrow];
inptr = input_data[inrow];
bias = 0; /* bias = 0,1,0,1,... for successive samples */
for (outcol = 0; outcol < output_cols; outcol++) {
*outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1])
+ bias) >> 1);
bias ^= 1; /* 0=>1, 1=>0 */
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
int inrow, outrow;
JDIMENSION outcol;
JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size;
register JSAMPROW inptr0, inptr1, outptr;
register int bias;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
* efficient.
*/
expand_right_edge(input_data, cinfo->max_v_samp_factor,
cinfo->image_width, output_cols * 2);
inrow = outrow = 0;
while (inrow < cinfo->max_v_samp_factor) {
outptr = output_data[outrow];
inptr0 = input_data[inrow];
inptr1 = input_data[inrow+1];
bias = 1; /* bias = 1,2,1,2,... for successive samples */
for (outcol = 0; outcol < output_cols; outcol++) {
*outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
int inrow, outrow;
JDIMENSION colctr;
JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size;
register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
INT32 membersum, neighsum, memberscale, neighscale;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
* efficient.
*/
expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
cinfo->image_width, output_cols * 2);
/* We don't bother to form the individual "smoothed" input pixel values;
* we can directly compute the output which is the average of the four
* smoothed values. Each of the four member pixels contributes a fraction
* (1-8*SF) to its own smoothed image and a fraction SF to each of the three
* other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
* output. The four corner-adjacent neighbor pixels contribute a fraction
* SF to just one smoothed pixel, or SF/4 to the final output; while the
* eight edge-adjacent neighbors contribute SF to each of two smoothed
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
JDIMENSION colctr;
JDIMENSION output_cols = compptr->width_in_blocks * compptr->DCT_h_scaled_size;
register JSAMPROW inptr, above_ptr, below_ptr, outptr;
INT32 membersum, neighsum, memberscale, neighscale;
int colsum, lastcolsum, nextcolsum;
/* Expand input data enough to let all the output samples be generated
* by the standard loop. Special-casing padded output would be more
* efficient.
*/
expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
cinfo->image_width, output_cols);
/* Each of the eight neighbor pixels contributes a fraction SF to the
* smoothed pixel, while the main pixel contributes (1-8*SF). In order
* to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
* Also recall that SF = smoothing_factor / 1024.
*/
memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */
neighscale = cinfo->smoothing_factor * 64; /* scaled SF */
src/Source/LibJPEG/jcsample.c view on Meta::CPAN
if (cinfo->smoothing_factor) {
downsample->methods[ci] = h2v2_smooth_downsample;
downsample->pub.need_context_rows = TRUE;
} else
#endif
downsample->methods[ci] = h2v2_downsample;
} else if ((h_in_group % h_out_group) == 0 &&
(v_in_group % v_out_group) == 0) {
smoothok = FALSE;
downsample->methods[ci] = int_downsample;
downsample->h_expand[ci] = (UINT8) (h_in_group / h_out_group);
downsample->v_expand[ci] = (UINT8) (v_in_group / v_out_group);
} else
ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
}
#ifdef INPUT_SMOOTHING_SUPPORTED
if (cinfo->smoothing_factor && !smoothok)
TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL);
#endif
}
src/Source/LibJPEG/jdsample.c view on Meta::CPAN
/* Per-component upsampling method pointers */
upsample1_ptr methods[MAX_COMPONENTS];
int next_row_out; /* counts rows emitted from color_buf */
JDIMENSION rows_to_go; /* counts rows remaining in image */
/* Height of an input row group for each component. */
int rowgroup_height[MAX_COMPONENTS];
/* These arrays save pixel expansion factors so that int_expand need not
* recompute them each time. They are unused for other upsampling methods.
*/
UINT8 h_expand[MAX_COMPONENTS];
UINT8 v_expand[MAX_COMPONENTS];
} my_upsampler;
typedef my_upsampler * my_upsample_ptr;
/*
* Initialize for an upsampling pass.
*/
METHODDEF(void)
src/Source/LibJPEG/jdsample.c view on Meta::CPAN
METHODDEF(void)
int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr, outptr;
register JSAMPLE invalue;
register int h;
JSAMPROW outend;
int h_expand, v_expand;
int inrow, outrow;
h_expand = upsample->h_expand[compptr->component_index];
v_expand = upsample->v_expand[compptr->component_index];
inrow = outrow = 0;
while (outrow < cinfo->max_v_samp_factor) {
/* Generate one output row with proper horizontal expansion */
inptr = input_data[inrow];
outptr = output_data[outrow];
outend = outptr + cinfo->output_width;
while (outptr < outend) {
invalue = *inptr++; /* don't need GETJSAMPLE() here */
for (h = h_expand; h > 0; h--) {
*outptr++ = invalue;
}
}
/* Generate any additional output rows by duplicating the first one */
if (v_expand > 1) {
jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
v_expand-1, cinfo->output_width);
}
inrow++;
outrow += v_expand;
}
}
/*
* Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
* It's still a box filter.
*/
METHODDEF(void)
src/Source/LibJPEG/jdsample.c view on Meta::CPAN
/* Special case for 2h1v upsampling */
upsample->methods[ci] = h2v1_upsample;
} else if (h_in_group * 2 == h_out_group &&
v_in_group * 2 == v_out_group) {
/* Special case for 2h2v upsampling */
upsample->methods[ci] = h2v2_upsample;
} else if ((h_out_group % h_in_group) == 0 &&
(v_out_group % v_in_group) == 0) {
/* Generic integral-factors upsampling method */
upsample->methods[ci] = int_upsample;
upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group);
upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group);
} else
ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
if (need_buffer) {
upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) jround_up((long) cinfo->output_width,
(long) cinfo->max_h_samp_factor),
(JDIMENSION) cinfo->max_v_samp_factor);
}
}
src/Source/LibJPEG/jerror.c view on Meta::CPAN
#include "jerror.h"
NULL
};
/*
* Error exit handler: must not return to caller.
*
* Applications may override this if they want to get control back after
* an error. Typically one would longjmp somewhere instead of exiting.
* The setjmp buffer can be made a private field within an expanded error
* handler object. Note that the info needed to generate an error message
* is stored in the error object, so you can generate the message now or
* later, at your convenience.
* You should make sure that the JPEG object is cleaned up (with jpeg_abort
* or jpeg_destroy) at some point.
*/
METHODDEF(noreturn_t)
error_exit (j_common_ptr cinfo)
{
src/Source/LibJPEG/jmemdos.c view on Meta::CPAN
/*
* jmemdos.c
*
* Copyright (C) 1992-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file provides an MS-DOS-compatible implementation of the system-
* dependent portion of the JPEG memory manager. Temporary data can be
* stored in extended or expanded memory as well as in regular DOS files.
*
* If you use this file, you must be sure that NEED_FAR_POINTERS is defined
* if you compile in a small-data memory model; it should NOT be defined if
* you use a large-data memory model. This file is not recommended if you
* are using a flat-memory-space 386 environment such as DJGCC or Watcom C.
* Also, this code will NOT work if struct fields are aligned on greater than
* 2-byte boundaries.
*
* Based on code contributed by Ge' Weijers.
*/
/*
* If you have both extended and expanded memory, you may want to change the
* order in which they are tried in jopen_backing_store. On a 286 machine
* expanded memory is usually faster, since extended memory access involves
* an expensive protected-mode-and-back switch. On 386 and better, extended
* memory is usually faster. As distributed, the code tries extended memory
* first (what? not everyone has a 386? :-).
*
* You can disable use of extended/expanded memory entirely by altering these
* definitions or overriding them from the Makefile (eg, -DEMS_SUPPORTED=0).
*/
#ifndef XMS_SUPPORTED
#define XMS_SUPPORTED 1
#endif
#ifndef EMS_SUPPORTED
#define EMS_SUPPORTED 1
#endif
src/Source/LibJPEG/jmemdos.c view on Meta::CPAN
info->write_backing_store = write_xms_store;
info->close_backing_store = close_xms_store;
TRACEMS1(cinfo, 1, JTRC_XMS_OPEN, ctx.dx);
return TRUE; /* succeeded */
}
#endif /* XMS_SUPPORTED */
/*
* Access methods for expanded memory.
*/
#if EMS_SUPPORTED
/* The EMS move specification structure requires word and long fields aligned
* at odd byte boundaries. Some compilers will align struct fields at even
* byte boundaries. While it's usually possible to force byte alignment,
* that causes an overall performance penalty and may pose problems in merging
* JPEG into a larger application. Instead we accept some rather dirty code
* here. Note this code would fail if the hardware did not allow odd-byte
src/Source/LibJPEG/jmemdos.c view on Meta::CPAN
/*
* Initial opening of a backing-store object.
*/
GLOBAL(void)
jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
long total_bytes_needed)
{
/* Try extended memory, then expanded memory, then regular file. */
#if XMS_SUPPORTED
if (open_xms_store(cinfo, info, total_bytes_needed))
return;
#endif
#if EMS_SUPPORTED
if (open_ems_store(cinfo, info, total_bytes_needed))
return;
#endif
if (open_file_store(cinfo, info, total_bytes_needed))
return;
src/Source/LibJPEG/jmemmac.c view on Meta::CPAN
GLOBAL(void)
jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
{
DisposePtr((Ptr) object);
}
/*
* "Large" objects are treated the same as "small" ones.
* NB: we include FAR keywords in the routine declarations simply for
* consistency with the rest of the IJG code; FAR should expand to empty
* on rational architectures like the Mac.
*/
GLOBAL(void FAR *)
jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
{
return (void FAR *) NewPtr(sizeofobject);
}
GLOBAL(void)
src/Source/LibJPEG/jmemsys.h view on Meta::CPAN
* by jmemmgr.c to manipulate the backing-store object; all other fields
* are private to the system-dependent backing store routines.
*/
#define TEMP_NAME_LENGTH 64 /* max length of a temporary file's name */
#ifdef USE_MSDOS_MEMMGR /* DOS-specific junk */
typedef unsigned short XMSH; /* type of extended-memory handles */
typedef unsigned short EMSH; /* type of expanded-memory handles */
typedef union {
short file_handle; /* DOS file handle if it's a temp file */
XMSH xms_handle; /* handle if it's a chunk of XMS */
EMSH ems_handle; /* handle if it's a chunk of EMS */
} handle_union;
#endif /* USE_MSDOS_MEMMGR */
#ifdef USE_MAC_MEMMGR /* Mac-specific junk */
src/Source/LibJPEG/jpeglib.h view on Meta::CPAN
#define jpeg_resync_to_restart jResyncRestart
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Default error-management setup */
EXTERN(struct jpeg_error_mgr *) jpeg_std_error
JPP((struct jpeg_error_mgr * err));
/* Initialization of JPEG compression objects.
* jpeg_create_compress() and jpeg_create_decompress() are the exported
* names that applications should call. These expand to calls on
* jpeg_CreateCompress and jpeg_CreateDecompress with additional information
* passed for version mismatch checking.
* NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
*/
#define jpeg_create_compress(cinfo) \
jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
(size_t) sizeof(struct jpeg_compress_struct))
#define jpeg_create_decompress(cinfo) \
jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
(size_t) sizeof(struct jpeg_decompress_struct))
src/Source/LibJPEG/libjpeg.txt view on Meta::CPAN
pixel having the same number of "component" or "sample" values (color
channels). You must specify how many components there are and the colorspace
interpretation of the components. Most applications will use RGB data
(three components per pixel) or grayscale data (one component per pixel).
PLEASE NOTE THAT RGB DATA IS THREE SAMPLES PER PIXEL, GRAYSCALE ONLY ONE.
A remarkable number of people manage to miss this, only to find that their
programs don't work with grayscale JPEG files.
There is no provision for colormapped input. JPEG files are always full-color
or full grayscale (or sometimes another colorspace such as CMYK). You can
feed in a colormapped image by expanding it to full-color format. However
JPEG often doesn't work very well with source data that has been colormapped,
because of dithering noise. This is discussed in more detail in the JPEG FAQ
and the other references mentioned in the README file.
Pixels are stored by scanlines, with each scanline running from left to
right. The component values for each pixel are adjacent in the row; for
example, R,G,B,R,G,B,R,G,B,... for 24-bit RGB color. Each scanline is an
array of data type JSAMPLE --- which is typically "unsigned char", unless
you've changed jmorecfg.h. (You can also change the RGB pixel layout, say
to B,G,R order, by modifying jmorecfg.h. But see the restrictions listed in
src/Source/LibJPEG/libjpeg.txt view on Meta::CPAN
You can reduce the size of the library by compiling out various optional
functions. To do this, undefine xxx_SUPPORTED symbols as necessary.
You can also save a few K by not having text error messages in the library;
the standard error message table occupies about 5Kb. This is particularly
reasonable for embedded applications where there's no good way to display
a message anyway. To do this, remove the creation of the message table
(jpeg_std_message_table[]) from jerror.c, and alter format_message to do
something reasonable without it. You could output the numeric value of the
message code number, for example. If you do this, you can also save a couple
more K by modifying the TRACEMSn() macros in jerror.h to expand to nothing;
you don't need trace capability anyway, right?
Portability considerations
--------------------------
The JPEG library has been written to be extremely portable; the sample
applications cjpeg and djpeg are slightly less so. This section summarizes
the design goals in this area. (If you encounter any bugs that cause the
library to be less portable than is claimed here, we'd appreciate hearing
src/Source/LibJPEG/rdbmp.c view on Meta::CPAN
ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
break;
}
}
/*
* Read one row of pixels.
* The image has been read into the whole_image array, but is otherwise
* unprocessed. We must read it out in top-to-bottom row order, and if
* it is an 8-bit image, we must expand colormapped pixels to 24bit format.
*/
METHODDEF(JDIMENSION)
get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
/* This version is for reading 8-bit colormap indexes */
{
bmp_source_ptr source = (bmp_source_ptr) sinfo;
register JSAMPARRAY colormap = source->colormap;
JSAMPARRAY image_ptr;
register int t;
src/Source/LibJPEG/rdtarga.c view on Meta::CPAN
/* State info for reading RLE-coded pixels; both counts must be init to 0 */
int block_count; /* # of pixels remaining in RLE block */
int dup_pixel_count; /* # of times to duplicate previous pixel */
/* This saves the correct pixel-row-expansion method for preload_image */
JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
cjpeg_source_ptr sinfo));
} tga_source_struct;
/* For expanding 5-bit pixel values to 8-bit with best rounding */
static const UINT8 c5to8bits[32] = {
0, 8, 16, 25, 33, 41, 49, 58,
66, 74, 82, 90, 99, 107, 115, 123,
132, 140, 148, 156, 165, 173, 181, 189,
197, 206, 214, 222, 230, 239, 247, 255
};
src/Source/LibJPEG/rdtarga.c view on Meta::CPAN
register int i;
for (i = 0; i < sinfo->pixel_size; i++) {
sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
}
}
METHODDEF(void)
read_rle_pixel (tga_source_ptr sinfo)
/* Read one Targa pixel from the input file, expanding RLE data as needed */
{
register FILE *infile = sinfo->pub.input_file;
register int i;
/* Duplicate previously read pixel? */
if (sinfo->dup_pixel_count > 0) {
sinfo->dup_pixel_count--;
return;
}
src/Source/LibJPEG/rdtarga.c view on Meta::CPAN
tga_source_ptr source = (tga_source_ptr) sinfo;
register int t;
register JSAMPROW ptr;
register JDIMENSION col;
ptr = source->pub.buffer[0];
for (col = cinfo->image_width; col > 0; col--) {
(*source->read_pixel) (source); /* Load next pixel into tga_pixel */
t = UCH(source->tga_pixel[0]);
t += UCH(source->tga_pixel[1]) << 8;
/* We expand 5 bit data to 8 bit sample width.
* The format of the 16-bit (LSB first) input word is
* xRRRRRGGGGGBBBBB
*/
ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
t >>= 5;
ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
t >>= 5;
ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
ptr += 3;
}
src/Source/LibJPEG/structure.txt view on Meta::CPAN
is much the same as for samples, and for the same reasons.
On machines where malloc() can't handle a request bigger than 64Kb, this data
structure limits us to rows of less than 512 JBLOCKs, or a picture width of
4000+ pixels. This seems an acceptable restriction.
On 80x86 machines, the bottom-level pointer types (JSAMPROW and JBLOCKROW)
must be declared as "far" pointers, but the upper levels can be "near"
(implying that the pointer lists are allocated in the DS segment).
We use a #define symbol FAR, which expands to the "far" keyword when
compiling on 80x86 machines and to nothing elsewhere.
*** Suspendable processing ***
In some applications it is desirable to use the JPEG library as an
incremental, memory-to-memory filter. In this situation the data source or
destination may be a limited-size buffer, and we can't rely on being able to
empty or refill the buffer at arbitrary times. Instead the application would
like to have control return from the library at buffer overflow/underrun, and
src/Source/LibJPEG/usage.txt view on Meta::CPAN
To avoid the Unisys LZW patent (now expired), djpeg produces uncompressed GIF
files. These are larger than they should be, but are readable by standard GIF
decoders.
HINTS FOR BOTH PROGRAMS
If more space is needed than will fit in the available main memory (as
determined by -maxmemory), temporary files will be used. (MS-DOS versions
will try to get extended or expanded memory first.) The temporary files are
often rather large: in typical cases they occupy three bytes per pixel, for
example 3*800*600 = 1.44Mb for an 800x600 image. If you don't have enough
free disk space, leave out -progressive and -optimize (for cjpeg) or specify
-onepass (for djpeg).
On MS-DOS, the temporary files are created in the directory named by the TMP
or TEMP environment variable, or in the current directory if neither of those
exist. Amiga implementations put the temp files in the directory named by
JPEGTMP:, so be sure to assign JPEGTMP: to a disk partition with adequate free
space.
src/Source/LibJPEG/usage.txt view on Meta::CPAN
-maxmemory value, even -maxmemory 0 to use the absolute minimum space. You
may want to recompile with a smaller default value if this happens often.
On machines that have "environment" variables, you can define the environment
variable JPEGMEM to set the default memory limit. The value is specified as
described for the -maxmemory switch. JPEGMEM overrides the default value
specified when the program was compiled, and itself is overridden by an
explicit -maxmemory switch.
On MS-DOS machines, -maxmemory is the amount of main (conventional) memory to
use. (Extended or expanded memory is also used if available.) Most
DOS-specific versions of this software do their own memory space estimation
and do not need you to specify -maxmemory.
JPEGTRAN
jpegtran performs various useful transformations of JPEG files.
It can translate the coded representation from one variant of JPEG to another,
for example from baseline JPEG to progressive JPEG or vice versa. It can also
perform some rearrangements of the image data, for example turning an image
src/Source/LibJPEG/wrgif.c view on Meta::CPAN
*
* GIF ordinarily uses variable-width symbols, and the decoder will expect
* to ratchet up the symbol width after a fixed number of symbols.
* To simplify the logic and keep the expansion penalty down, we emit a
* GIF Clear code to reset the decoder just before the width would ratchet up.
* Thus, all the symbols in the output file will have the same bit width.
* Note that emitting the Clear codes at the right times is a mere matter of
* counting output symbols and is in no way dependent on the LZW patent.
*
* With a small basic pixel width (low color count), Clear codes will be
* needed very frequently, causing the file to expand even more. So this
* simplistic approach wouldn't work too well on bilevel images, for example.
* But for output of JPEG conversions the pixel width will usually be 8 bits
* (129 to 256 colors), so the overhead added by Clear symbols is only about
* one symbol in every 256.
*/
LOCAL(void)
compress_init (gif_dest_ptr dinfo, int i_bits)
/* Initialize pseudo-compressor */
{
src/Source/LibOpenJPEG/j2k.c view on Meta::CPAN
if (parameters->mct_data) {
opj_free(parameters->mct_data);
parameters->mct_data = 00;
}
}
static OPJ_BOOL opj_j2k_add_mhmarker(opj_codestream_index_t *cstr_index, OPJ_UINT32 type, OPJ_OFF_T pos, OPJ_UINT32 len)
{
assert(cstr_index != 00);
/* expand the list? */
if ((cstr_index->marknum + 1) > cstr_index->maxmarknum) {
opj_marker_info_t *new_marker;
cstr_index->maxmarknum = (OPJ_UINT32)(100 + (OPJ_FLOAT32) cstr_index->maxmarknum);
new_marker = (opj_marker_info_t *) opj_realloc(cstr_index->marker, cstr_index->maxmarknum *sizeof(opj_marker_info_t));
if (! new_marker) {
opj_free(cstr_index->marker);
cstr_index->marker = NULL;
cstr_index->maxmarknum = 0;
cstr_index->marknum = 0;
/* opj_event_msg(p_manager, EVT_ERROR, "Not enough memory to add mh marker\n"); */
src/Source/LibOpenJPEG/j2k.c view on Meta::CPAN
cstr_index->marker[cstr_index->marknum].len = (OPJ_INT32)len;
cstr_index->marknum++;
return OPJ_TRUE;
}
static OPJ_BOOL opj_j2k_add_tlmarker(OPJ_UINT32 tileno, opj_codestream_index_t *cstr_index, OPJ_UINT32 type, OPJ_OFF_T pos, OPJ_UINT32 len)
{
assert(cstr_index != 00);
assert(cstr_index->tile_index != 00);
/* expand the list? */
if ((cstr_index->tile_index[tileno].marknum + 1) > cstr_index->tile_index[tileno].maxmarknum) {
opj_marker_info_t *new_marker;
cstr_index->tile_index[tileno].maxmarknum = (OPJ_UINT32)(100 + (OPJ_FLOAT32) cstr_index->tile_index[tileno].maxmarknum);
new_marker = (opj_marker_info_t *) opj_realloc(
cstr_index->tile_index[tileno].marker,
cstr_index->tile_index[tileno].maxmarknum *sizeof(opj_marker_info_t));
if (! new_marker) {
opj_free(cstr_index->tile_index[tileno].marker);
cstr_index->tile_index[tileno].marker = NULL;
cstr_index->tile_index[tileno].maxmarknum = 0;
src/Source/LibOpenJPEG/openjpeg.h view on Meta::CPAN
OPJ_UINT32 numlayers;
/** multi-component transform identifier */
OPJ_UINT32 mct;
/** information concerning tile component parameters*/
opj_tccp_info_t *tccp_info;
} opj_tile_info_v2_t;
/**
* Information structure about the codestream (FIXME should be expand and enhance)
*/
typedef struct opj_codestream_info_v2 {
/* Tile info */
/** tile origin in x = XTOsiz */
OPJ_UINT32 tx0;
/** tile origin in y = YTOsiz */
OPJ_UINT32 ty0;
/** tile size in x = XTsiz */
OPJ_UINT32 tdx;
/** tile size in y = YTsiz */
src/Source/LibOpenJPEG/openjpeg.h view on Meta::CPAN
/* <<UniPG */
/** packet number */
OPJ_UINT32 nb_packet;
/** information concerning packets inside tile */
opj_packet_info_t *packet_index;
} opj_tile_index_t;
/**
* Index structure of the codestream (FIXME should be expand and enhance)
*/
typedef struct opj_codestream_index {
/** main header start position (SOC position) */
OPJ_OFF_T main_head_start;
/** main header end position (first SOT position) */
OPJ_OFF_T main_head_end;
/** codestream's size */
OPJ_UINT64 codestream_size;
src/Source/LibPNG/CHANGES view on Meta::CPAN
Relocated the png_composite macros from pngrtran.c to png.h (Greg).
Added makefile.sco (contributed by Mike Hopkirk).
Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
More work on the Paeth-filtering, achieving imperceptible speedup
(A Kleinert).
More work on loop optimization which may help when compiled with C++
compilers.
Added warnings when people try to use transforms they've defined out.
Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
Version 1.0.1c [May 11, 1998]
Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
filler bytes should have been 0xff instead of 0xf.
Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
for consistency, in pngconf.h
Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
src/Source/LibPNG/CHANGES view on Meta::CPAN
png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
Added function png_set_empty_plte_permitted() to make libpng useable
in MNG applications.
Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
consistent with PNG-1.2, and allow variance of 500 before complaining.
Added assembler code contributed by Intel in file pngvcrd.c and modified
makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
Gilles Vollant)
Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
Added some aliases for png_set_expand() in pngrtran.c, namely
png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
(Greg Roelofs, in "PNG: The Definitive Guide").
Added makefile.beo for BEOS on X86, contributed by Sander Stok.
Version 1.0.3b [August 26, 1999]
Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
Changed leading blanks to tabs in all makefiles.
Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
Made alternate versions of png_set_expand() in pngrtran.c, namely
png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
(Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases.
Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
Revised calculation of num_blocks in pngmem.c to avoid a potentially
negative shift distance, whose results are undefined in the C language.
Added a check in pngset.c to prevent writing multiple tIME chunks.
Added a check in pngwrite.c to detect invalid small window_bits sizes.
Version 1.0.3d [September 4, 1999]
Fixed type casting of igamma in pngrutil.c
Added new png_expand functions to scripts/pngdef.pas and pngos2.def
Added a demo read_user_transform_fn that examines the row filters in pngtest.c
Version 1.0.4 [September 24, 1999]
Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
Made several minor corrections to pngtest.c
Renamed the makefiles with longer but more user friendly extensions.
Copied the PNG copyright and license to a separate LICENSE file.
Revised documentation, png.h, and example.c to remove reference to
"viewing_gamma" which no longer appears in the PNG specification.
src/Source/LibPNG/CHANGES view on Meta::CPAN
Cosmetic changes in pngtest.c
Version 1.0.5q [February 5, 2000]
Relocated the makefile.solaris warning about PATH problems.
Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
Revised makefile.gcmmx
Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
Version 1.0.5r [February 7, 2000]
Removed superfluous prototype for png_get_itxt from png.h
Fixed a bug in pngrtran.c that improperly expanded the background color.
Return *num_text=0 from png_get_text() when appropriate, and fix documentation
of png_get_text() in libpng.txt/libpng.3.
Version 1.0.5s [February 18, 2000]
Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
new error handler that's planned for the next libpng release, and changed
example.c, pngtest.c, and contrib programs to use this macro.
Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
Fixed a bug in png_read_png() that caused it to fail to expand some images
that it should have expanded.
Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
in pngget.c
Changed the allocation of palette, history, and trans arrays back to
the version 1.0.5 method (linking instead of copying) which restores
backward compatibility with version 1.0.5. Added some remarks about
that in example.c. Added "free_me" member to info_ptr and png_ptr
and added png_free_data() function.
Updated makefile.linux and makefile.gccmmx to make directories conditionally.
Made cosmetic changes to pngasmrd.h
Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
src/Source/LibPNG/CHANGES view on Meta::CPAN
Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
is defined.
Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
overrun when old applications fill the info_ptr->text structure directly.
Added PNGAPI macro, and added it to the definitions of all exported functions.
Relocated version macro definitions ahead of the includes of zlib.h and
pngconf.h in png.h.
Version 1.0.7beta12 [May 12, 2000]
Revised pngset.c to avoid a problem with expanding the png_debug macro.
Deleted some extraneous defines from pngconf.h
Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
Added png_access_version_number() function.
Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
Expanded libpng.3/libpng.txt information about png_data_freer().
Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
warnings instead of errors, as pngrutil.c does.
src/Source/LibPNG/CHANGES view on Meta::CPAN
Made some makefiles accept "exec_prefix".
Version 1.2.9beta8 [March 9, 2006]
Fixed some "#if defined (..." which should be "#if defined(..."
Bug introduced in libpng-1.2.8.
Fixed inconsistency in definition of png_default_read_data()
Restored blank that was lost from makefile.sggcc "clean" target in beta7.
Revised calculation of "current" and "major" for irix in ltmain.sh
Changed "mkdir" to "MKDIR_P" in some makefiles.
Separated PNG_EXPAND and PNG_EXPAND_tRNS.
Added png_set_expand_gray_1_2_4_to_8() and deprecated
png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
Version 1.2.9beta9 [March 10, 2006]
Include "config.h" in pngconf.h when available.
Added some checks for NULL png_ptr or NULL info_ptr (timeless)
Version 1.2.9beta10 [March 20, 2006]
Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
Made pnggccrd.c PIC-compliant (Christian Aichinger).
Added makefile.mingw (Wolfgang Glas).
Revised pngconf.h MMX checking.
src/Source/LibPNG/CHANGES view on Meta::CPAN
Added "const" to some array declarations.
Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
Version 1.2.17rc1 [May 4, 2007]
No changes.
Version 1.2.17rc2 [May 8, 2007]
Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
calling set_unknown_chunk_location() need them.
Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
png_set_expand_gray_1_2_4_to_8().
Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
can be free'ed in case of error. Revised unknown chunk handling in
pngrutil.c and pngpread.c to use this structure.
Version 1.2.17rc3 [May 8, 2007]
Revised symbol-handling in configure script.
Version 1.2.17rc4 [May 10, 2007]
Revised unknown chunk handling to avoid storing unknown critical chunks.
src/Source/LibPNG/CHANGES view on Meta::CPAN
Version 1.2.18 [May 15, 2007]
Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
Version 1.2.19beta1 [May 18, 2007]
Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
change of libpng-1.2.17beta2. Changed other "const" to "PNG_CONST"
Changed some handling of unused parameters, to avoid compiler warnings.
"if (unused == NULL) return;" becomes "unused = unused".
Version 1.2.19beta2 [May 18, 2007]
Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
Version 1.2.19beta3 [May 19, 2007]
Add some "png_byte" typecasts in png_check_keyword() and write new_key
instead of key in zTXt chunk (Kevin Ryde).
Version 1.2.19beta4 [May 21, 2007]
Add png_snprintf() function and use it in place of sprint() for improved
defense against buffer overflows.
Version 1.2.19beta5 [May 21, 2007]
src/Source/LibPNG/CHANGES view on Meta::CPAN
Version 1.4.0beta34 [September 6, 2008]
Shortened tIME_string to 29 bytes in pngtest.c
Fixed off-by-one error introduced in png_push_read_zTXt() function in
libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
Version 1.4.0beta35 [October 6, 2008]
Changed "trans_values" to "trans_color".
Changed so-number from 0 to 14. Some OS do not like 0.
Revised makefile.darwin to fix shared library numbering.
Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
in example.c (debian bug report)
Version 1.4.0beta36 [October 25, 2008]
Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
Version 1.4.0beta37 [November 13, 2008]
Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
and pngwrite.c
Version 1.4.0beta38 [November 22, 2008]
src/Source/LibPNG/CHANGES view on Meta::CPAN
scripts/README.txt
Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
Version 1.4.0beta103 [November 21, 2009]
Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
Align row_buf on 16-byte boundary in memory.
Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
to png_flush() after png_write_IEND(). See 1.4.0beta32, 1.4.0beta50
changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES. Someone
needs this feature.
Make the 'png_jmpbuf' macro expand to a call that records the correct
longjmp function as well as returning a pointer to the setjmp
jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
(John Bowler)
Version 1.4.0beta104 [November 22, 2009]
Removed png_longjmp_ptr from scripts/*.def and libpng.3
Rebuilt configure scripts with autoconf-2.65
Version 1.4.0beta105 [November 25, 2009]
Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
src/Source/LibPNG/CHANGES view on Meta::CPAN
Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
Added png_get_current_row_number and png_get_current_pass_number for the
benefit of the user transform callback.
Added png_process_data_pause and png_process_data_skip for the benefit of
progressive readers that need to stop data processing or want to optimize
skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
Version 1.5.1beta09 [January 24, 2011]
Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
pngvalid contains tests of transforms, which tests are currently disabled
because they are incompletely tested. gray_to_rgb was failing to expand
the bit depth for smaller bit depth images; this seems to be a long
standing error and resulted, apparently, in invalid output
(CVE-2011-0408, CERT VU#643140). The documentation did not accurately
describe what libpng really does when converting RGB to gray.
Version 1.5.1beta10 [January 27, 2010]
Fixed incorrect examples of callback prototypes in the manual, that were
introduced in libpng-1.0.0.
In addition the order of the png_get_uint macros with respect to the
relevant function definitions has been reversed. This helps the
src/Source/LibPNG/CHANGES view on Meta::CPAN
Version 1.5.3beta04 [April 27, 2011]
Updated pngtest.png with the new zlib CMF optimization.
Cleaned up conditional compilation code and of background/gamma handling
Internal changes only except a new option to avoid compiling the
png_build_grayscale_palette API (which is not used at all internally.)
The main change is to move the transform tests (READ_TRANSFORMS,
WRITE_TRANSFORMS) up one level to the caller of the APIs. This avoids
calls to spurious functions if all transforms are disabled and slightly
simplifies those functions. Pngvalid modified to handle this.
A minor change is to stop the strip_16 and expand_16 interfaces from
disabling each other; this allows the future alpha premultiplication
code to use 16-bit intermediate values while still producing 8-bit output.
png_do_background and png_do_gamma have been simplified to take a single
pointer to the png_struct rather than pointers to every item required
from the png_struct. This makes no practical difference to the internal
code.
A serious bug in the pngvalid internal routine 'standard_display_init' has
been fixed - this failed to initialize the red channel and accidentally
initialized the alpha channel twice.
Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
src/Source/LibPNG/CHANGES view on Meta::CPAN
chunk had been deflated - much too late. In this change internal
functions were added to claim/release the z_stream and, hopefully, make
the code more robust. Also deflateEnd checking is added - previously
libpng would ignore an error at the end of the stream.
Version 1.5.3beta06 [May 8, 2011]
Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
Implemented premultiplied alpha support: png_set_alpha_mode API
Version 1.5.3beta07 [May 11, 2011]
Added expand_16 support to the high level interface.
Added named value and 'flag' gamma support to png_set_gamma. Made a minor
change from the previous (unreleased) ABI/API to hide the exact value used
for Macs - it's not a good idea to embed this in the ABI!
Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
from pngpriv.h to png.h because they must be visible to applications
that call png_set_unknown_chunks().
Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
before IDAT.
Version 1.5.3beta08 [May 16, 2011]
src/Source/LibPNG/CHANGES view on Meta::CPAN
sRGB/Rec 709 values are still used. This introduced a divide-by-zero
bug in png_handle_cHRM().
The bKGD chunk no longer overwrites the background value set by
png_set_background(), allowing the latter to be used before the file
header is read. It never performed any useful function to override
the default anyway.
Added memory overwrite and palette image checks to pngvalid.c
Previously palette image code was poorly checked. Since the transformation
code has a special palette path in most cases this was a severe weakness.
Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
expanding an indexed image, always expand to RGBA if transparency is
present.
Version 1.5.3beta09 [May 17, 2011]
Reversed earlier 1.5.3 change of transformation order; move png_expand_16
back where it was. The change doesn't work because it requires 16-bit
gamma tables when the code only generates 8-bit ones. This fails
silently; the libpng code just doesn't do any gamma correction. Moving
the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
these are clearly better than none!
Version 1.5.3beta10 [May 20, 2011]
png_set_background() and png_expand_16() did not work together correctly.
This problem is present in 1.5.2; if png_set_background is called with
need_expand false and the matching 16 bit color libpng erroneously just
treats it as an 8-bit color because of where png_do_expand_16 is in the
transform list. This simple fix reduces the supplied colour to 8-bits,
so it gets smashed, but this is better than the current behavior.
Added tests for expand16, more fixes for palette image tests to pngvalid.
Corrects the code for palette image tests and disables attempts to
validate palette colors.
Version 1.5.3rc01 [June 3, 2011]
No changes.
Version 1.5.3rc02 [June 8, 2011]
Fixed uninitialized memory read in png_format_buffer() (Bug report by
Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
src/Source/LibPNG/CHANGES view on Meta::CPAN
Version 1.5.4beta02 [June 14, 2011]
Fixed and clarified LEGACY 16-to-8 scaling code.
Added png_set_chop_16() API, to match inaccurate results from previous
libpng versions.
Removed the ACCURATE and LEGACY options (they are no longer useable)
Use the old scaling method for background if png_set_chop_16() was
called.
Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
Version 1.5.4beta03 [June 15, 2011]
Fixed a problem in png_do_expand_palette() exposed by optimization in
1.5.3beta06
Also removed a spurious and confusing "trans" member ("trans") from png_info.
The palette expand optimization prevented expansion to an intermediate RGBA
form if tRNS was present but alpha was marked to be stripped; this exposed
a check for tRNS in png_do_expand_palette() which is inconsistent with the
code elsewhere in libpng.
Correction to the expand_16 code; removed extra instance of
png_set_scale_16_to_8 from pngpriv.h
Version 1.5.4beta04 [June 16, 2011]
Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again. If this is
not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
Version 1.5.4beta05 [June 16, 2011]
src/Source/LibPNG/CHANGES view on Meta::CPAN
to '"%s" m' to improve portability among compilers.
Changed png_free_default() to free() in pngtest.c
Version 1.6.8rc01 [December 12, 2013]
Tidied up pngfix inits and fixed pngtest no-write builds.
Version 1.6.8rc02 [December 14, 2013]
Handle zero-length PLTE chunk or NULL palette with png_error()
instead of png_chunk_report(), which by default issues a warning
rather than an error, leading to later reading from a NULL pointer
(png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
and VU#650142. Libpng-1.6.1 through 1.6.7 are vulnerable.
Libpng-1.6.0 and earlier do not have this bug.
Version 1.6.8 [December 19, 2013]
No changes.
Version 1.6.9beta01 [December 26, 2013]
Bookkeeping: Moved functions around (no changes). Moved transform
function definitions before the place where they are called so that
they can be made static. Move the intrapixel functions and the
src/Source/LibPNG/CHANGES view on Meta::CPAN
Version 1.6.11beta03 [April 6, 2014]
Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
Optionally use __builtin_bswap16() in png_do_swap().
Version 1.6.11beta04 [April 19, 2014]
Made progressive reading of interlaced images consistent with the
behavior of the sequential reader and consistent with the manual, by
moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
row_callback now receives the proper pass number and unexpanded rows, when
png_combine_row() isn't built or used, and png_set_interlace_handling()
is not called.
Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
Version 1.6.11beta05 [April 26, 2014]
Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
Relocated closing bracket of the sRGB profile test loop to avoid getting
"Not recognizing known sRGB profile that has been edited" warning for
ICC V2 profiles that lack the MD5 signature in the profile header.
src/Source/LibPNG/example.c view on Meta::CPAN
/* Change the order of packed pixels to least significant bit first
* (not useful if you are using png_set_packing). */
png_set_packswap(png_ptr);
/* Expand paletted colors into true RGB triplets */
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
/* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand_gray_1_2_4_to_8(png_ptr);
/* Expand paletted or RGB images with transparency to full alpha channels
* so the data will be available as RGBA quartets.
*/
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0)
png_set_tRNS_to_alpha(png_ptr);
/* Set the background color to draw transparent and alpha images over.
* It is possible to set the red, green, and blue components directly
* for paletted images instead of supplying a palette index. Note that
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
If you call png_set_gamma() after png_set_alpha_mode() you
will override the linear encoding. Instead the
pre-multiplied pixel values will be gamma encoded but
the alpha channel will still be linear. This may
actually match the requirements of some broken software,
but it is unlikely.
While linear 8-bit data is often used it has
insufficient precision for any image with a reasonable
dynamic range. To avoid problems, and if your software
supports it, use png_set_expand_16() to force all
components to 16 bits.
PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD
except that completely opaque pixels are gamma encoded according to
the screen_gamma value. Pixels with alpha less than 1.0
will still have linear components.
Use this format if you have control over your
compositing software and so don't do other arithmetic
(such as scaling) on the data you get from libpng. Your
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
screen_gamma);
You can do color correction on the result (libpng does not currently
support color correction internally). When you handle the alpha channel
you need to undo the gamma encoding and multiply out the alpha.
png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
screen_gamma);
png_set_expand_16(png_ptr);
If you are using the high level interface, don't call png_set_expand_16();
instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
With this mode you can't do color correction, but you can do arithmetic,
including composition and scaling, on the data without further processing.
png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
screen_gamma);
You can avoid the expansion to 16-bit components with this mode, but you
lose the ability to scale the image or perform other linear arithmetic.
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
This is the classic Jim Blinn approach and will work in academic
environments where everything is done by the book. It has the shortcoming
of assuming that input PNG data with no gamma information is linear - this
is unlikely to be correct unless the PNG files where generated locally.
Most of the time the output precision will be so low as to show
significant banding in dark areas of the image.
png_set_expand_16(pp);
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
This is a somewhat more realistic Jim Blinn inspired approach. PNG files
are assumed to have the sRGB encoding if not marked with a gamma value and
the output is always 16 bits per component. This permits accurate scaling
and processing of the data. If you know that your input PNG files were
generated locally you might need to replace PNG_DEFAULT_sRGB with the
correct value for your system.
png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
must always be converted to at least 8-bit format. (Even though low bit depth
grayscale images can't have an alpha channel they can have a transparent
color!)
You set the transforms you need later, either as flags to the high level
interface or libpng API calls for the low level interface. For reference the
settings and API calls required are:
8-bit values:
PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
png_set_expand(png_ptr); png_set_scale_16(png_ptr);
If you must get exactly the same inaccurate results
produced by default in versions prior to libpng-1.5.4,
use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
instead.
16-bit values:
PNG_TRANSFORM_EXPAND_16
png_set_expand_16(png_ptr);
In either case palette image data will be expanded to RGB. If you just want
color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
to the list.
Calling png_set_background before the PNG file header is read will not work
prior to libpng-1.5.4. Because the failure may result in unexpected warnings or
errors it is therefore much safer to call png_set_background after the head has
been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be
used with the high level interface.
The high-level read interface
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to
8-bit accurately
PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to
8-bit less accurately
PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_EXPAND Perform set_expand()
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
x and y are 0] if the data is not present or if the
chunk is present but the unit is the pixel. The
remark about inexact inch conversions applies here
as well, because a value in inches can't always be
converted to microns and back without some loss
of precision.
For more information, see the
PNG specification for chunk contents. Be careful with trusting
rowbytes, as some of the transformations could increase the space
needed to hold a row (expand, filler, gray_to_rgb, etc.).
See png_read_update_info(), below.
A quick word about text_ptr and num_text. PNG stores comments in
keyword/text pairs, one pair per chunk, with no limit on the number
of text chunks, and a 2^31 byte limit on their size. While there are
suggested keywords, there is no requirement to restrict the use to these
strings. It is strongly suggested that keywords and text be sensible
to humans (that's the point), so don't use abbreviations. Non-printing
symbols are not allowed. See the PNG specification for more details.
There is also no requirement to have text after the keyword.
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
Transformations you request are ignored if they don't have any meaning for a
particular input data format. However some transformations can have an effect
as a result of a previous transformation. If you specify a contradictory set of
transformations, for example both adding and removing the alpha channel, you
cannot predict the final result.
The color used for the transparency values should be supplied in the same
format/depth as the current image data. It is stored in the same format/depth
as the image data in a tRNS chunk, so this is what libpng expects for this data.
The color used for the background value depends on the need_expand argument as
described below.
Data will be decoded into the supplied row buffers packed into bytes
unless the library has been told to transform it into another format.
For example, 4 bit/pixel paletted or grayscale data will be returned
2 pixels/byte with the leftmost pixel in the high-order bits of the
byte, unless png_set_packing() is called. 8-bit RGB data will be stored
in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
is called to insert filler bytes, either before or after each RGB triplet.
16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
grayscale images with bit depths of 2 or 4 or if there is a multiple-image
viewing application that wishes to treat all images in the same way.
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
if (png_get_valid(png_ptr, info_ptr,
PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY &&
bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
The first two functions are actually aliases for png_set_expand(), added
in libpng version 1.0.4, with the function names expanded to improve code
readability. In some future version they may actually do different
things.
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
added. It expands the sample depth without changing tRNS to alpha.
As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as
png_set_expand(); however, the resultant channels have 16 bits rather than 8.
Use this when the output color or gray channels are made linear to avoid fairly
severe accuracy loss.
if (bit_depth < 16)
png_set_expand_16(png_ptr);
PNG can have files with 16 bits per channel. If you only can handle
8 bits per channel, this will strip the pixels down to 8-bit.
if (bit_depth == 16)
#if PNG_LIBPNG_VER >= 10504
png_set_scale_16(png_ptr);
#else
png_set_strip_16(png_ptr);
#endif
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
4O lA GBA A T T GA GT GT GA GT GT BA + GBA G
6A CA PA CA C C A T tT PA P P C CBA + BA
6O CA PBA CA C C A tT T PA P P CBA C BA +
Within the matrix,
"+" identifies entries where 'from' and 'to' are the same.
"-" means the transformation is not supported.
"." means nothing is necessary (a tRNS chunk can just be ignored).
"t" means the transformation is obtained by png_set_tRNS.
"A" means the transformation is obtained by png_set_add_alpha().
"X" means the transformation is obtained by png_set_expand().
"1" means the transformation is obtained by
png_set_expand_gray_1_2_4_to_8() (and by png_set_expand()
if there is no transparency in the original or the final
format).
"C" means the transformation is obtained by png_set_gray_to_rgb().
"G" means the transformation is obtained by png_set_rgb_to_gray().
"P" means the transformation is obtained by
png_set_expand_palette_to_rgb().
"p" means the transformation is obtained by png_set_packing().
"Q" means the transformation is obtained by png_set_quantize().
"T" means the transformation is obtained by
png_set_tRNS_to_alpha().
"B" means the transformation is obtained by
png_set_background(), or png_strip_alpha().
When an entry has multiple transforms listed all are required to cause the
right overall transformation. When two transforms are separated by a comma
either will do the job. When transforms are enclosed in [] the transform should
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
is the level of opacity. If you need the alpha channel in an image to
be the level of transparency instead of opacity, you can invert the
alpha channel (or the tRNS chunk data) after it's read, so that 0 is
fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
images) is fully transparent, with
png_set_invert_alpha(png_ptr);
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
they can, resulting in, for example, 8 pixels per byte for 1 bit
files. This code expands to 1 pixel per byte without changing the
values of the pixels:
if (bit_depth < 8)
png_set_packing(png_ptr);
PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
stored in a PNG image have been "scaled" or "shifted" up to the next
higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
to 8 bits/sample in the range [0, 255]). However, it is also possible
to convert the PNG pixel data back to the original bit depth of the
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
png_set_shift(png_ptr, sig_bit);
PNG files store 3-color pixels in red, green, blue order. This code
changes the storage of the pixels to blue, green, red:
if (color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA)
png_set_bgr(png_ptr);
PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
into 4 or 8 bytes for windowing systems that need them in this format:
if (color_type == PNG_COLOR_TYPE_RGB)
png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
where "filler" is the 8 or 16-bit number to fill with, and the location is
either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
you want the filler before the RGB or after. This transformation
does not affect images that already have full alpha channels. To add an
opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
composite images with alpha or simple transparency against the supplied
background color. For compatibility with versions of libpng earlier than
libpng-1.5.4 it is recommended that you call the function after reading the file
header, even if you don't want to use the color in a bKGD chunk, if one exists.
If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
you may use this color, or supply another color more suitable for
the current display (e.g., the background color from a web page). You
need to tell libpng how the color is represented, both the format of the
component values in the color (the number of bits) and the gamma encoding of the
color. The function takes two arguments, background_gamma_mode and need_expand
to convey this information; however, only two combinations are likely to be
useful:
png_color_16 my_background;
png_color_16p image_background;
if (png_get_bKGD(png_ptr, info_ptr, &image_background))
png_set_background(png_ptr, image_background,
PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
else
png_set_background(png_ptr, &my_background,
PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
The second call was described above - my_background is in the format of the
final, display, output produced by libpng. Because you now know the format of
the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
output and to retain palette images (the palette colors will be modified
appropriately and the tRNS chunk removed.) However, if you are doing this,
take great care not to ask for transformations without checking first that
they apply!
In the first call the background color has the original bit depth and color type
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
get somewhat harder. The only current (PNG Specification version 1.2)
interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7);
a somewhat complicated 2D interlace scheme, known as Adam7, that
breaks down an image into seven smaller images of varying size, based
on an 8x8 grid. This number is defined (from libpng 1.5) as
PNG_INTERLACE_ADAM7_PASSES in png.h
libpng can fill out those images or it can give them to you "as is".
It is almost always better to have libpng handle the interlacing for you.
If you want the images filled out, there are two ways to do that. The one
mentioned in the PNG specification is to expand each pixel to cover
those pixels that have not been read yet (the "rectangle" method).
This results in a blocky image for the first pass, which gradually
smooths out as more pixels are read. The other method is the "sparkle"
method, where pixels are drawn only in their final locations, with the
rest of the image remaining whatever colors they were initialized to
before the start of the read. The first method usually looks better,
but tends to be slower, as there are more pixels to put in the rows.
If, as is likely, you want libpng to expand the images, call this before
calling png_start_read_image() or png_read_update_info():
if (interlace_type == PNG_INTERLACE_ADAM7)
number_of_passes
= png_set_interlace_handling(png_ptr);
This will return the number of passes needed. Currently, this is seven,
but may change if another interlace type is added. This function can be
called even if the file is not interlaced, where it will return one pass.
You then need to read the whole image 'number_of_passes' times. Each time
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
png_debug1(level, message, p1)
png_debug2(level, message, p1, p2)
in which "level" is compared to PNG_DEBUG to decide whether to print
the message, "message" is the formatted string to be printed,
and p1 and p2 are parameters that are to be embedded in the string
according to printf-style formatting directives. For example,
png_debug1(2, "foo=%d", foo);
is expanded to
if (PNG_DEBUG > 2)
fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
can still use PNG_DEBUG to control your own debugging:
#ifdef PNG_DEBUG
fprintf(stderr, ...
#endif
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
The png_malloc_warn() function was added at libpng-1.2.3. This issues
a png_warning and returns NULL instead of aborting when it fails to
acquire the requested memory allocation.
Support for setting user limits on image width and height was enabled
by default. The functions png_set_user_limits(), png_get_user_width_max(),
and png_get_user_height_max() were added at libpng-1.2.6.
The png_set_add_alpha() function was added at libpng-1.2.7.
The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9.
Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the
tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is
deprecated.
A number of macro definitions in support of runtime selection of
assembler code features (especially Intel MMX code support) were
added at libpng-1.2.0:
PNG_ASM_FLAG_MMX_SUPPORT_COMPILED
PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
deprecated since libpng-1.0.16 and libpng-1.2.6.
The function
png_check_sig(sig, num)
was replaced with
!png_sig_cmp(sig, 0, num)
It has been deprecated since libpng-0.90.
The function
png_set_gray_1_2_4_to_8()
which also expands tRNS to alpha was replaced with
png_set_expand_gray_1_2_4_to_8()
which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
Private libpng prototypes and macro definitions were moved from
png.h and pngconf.h into a new pngpriv.h header file.
Functions png_set_benign_errors(), png_benign_error(), and
png_chunk_benign_error() were added.
src/Source/LibPNG/libpng-manual.txt view on Meta::CPAN
png_set_mmx_thresholds(), png_get_asm_flags(),
png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
png_set_asm_flags(), and png_mmx_supported()
We removed the obsolete png_check_sig(), png_memcpy_check(), and
png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(),
and memset(), respectively.
The function png_set_gray_1_2_4_to_8() was removed. It has been
deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
png_set_expand_gray_1_2_4_to_8() because the former function also
expanded any tRNS chunk to an alpha channel.
Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32
were added and are used by default instead of the corresponding
functions. Unfortunately,
from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
function) incorrectly returned a value of type png_uint_32.
We changed the prototype for png_malloc() from
png_malloc(png_structp png_ptr, png_uint_32 size)
to
src/Source/LibPNG/libpng.3 view on Meta::CPAN
\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP
\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP
\fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
\fBvoid png_set_background_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, png_uint_32 \fIbackground_gamma\fP\fB);\fP
\fBvoid png_set_benign_errors (png_structp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
\fBvoid png_set_check_for_invalid_index(png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
\fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB,...
src/Source/LibPNG/libpng.3 view on Meta::CPAN
\fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
\fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
\fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
\fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP
\fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP
\fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_expand_16 (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
\fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
\fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
\fBvoid png_set_filter_heuristics_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_fixed_point_p \fP\fIfilter_weights\fP\fB, png_fixed_point_p \fIfilter_costs\fP\fB);\fP
\fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP
src/Source/LibPNG/libpng.3 view on Meta::CPAN
If you call png_set_gamma() after png_set_alpha_mode() you
will override the linear encoding. Instead the
pre-multiplied pixel values will be gamma encoded but
the alpha channel will still be linear. This may
actually match the requirements of some broken software,
but it is unlikely.
While linear 8-bit data is often used it has
insufficient precision for any image with a reasonable
dynamic range. To avoid problems, and if your software
supports it, use png_set_expand_16() to force all
components to 16 bits.
PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD
except that completely opaque pixels are gamma encoded according to
the screen_gamma value. Pixels with alpha less than 1.0
will still have linear components.
Use this format if you have control over your
compositing software and so don't do other arithmetic
(such as scaling) on the data you get from libpng. Your
src/Source/LibPNG/libpng.3 view on Meta::CPAN
png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
screen_gamma);
You can do color correction on the result (libpng does not currently
support color correction internally). When you handle the alpha channel
you need to undo the gamma encoding and multiply out the alpha.
png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
screen_gamma);
png_set_expand_16(png_ptr);
If you are using the high level interface, don't call png_set_expand_16();
instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
With this mode you can't do color correction, but you can do arithmetic,
including composition and scaling, on the data without further processing.
png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
screen_gamma);
You can avoid the expansion to 16-bit components with this mode, but you
lose the ability to scale the image or perform other linear arithmetic.
src/Source/LibPNG/libpng.3 view on Meta::CPAN
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
This is the classic Jim Blinn approach and will work in academic
environments where everything is done by the book. It has the shortcoming
of assuming that input PNG data with no gamma information is linear - this
is unlikely to be correct unless the PNG files where generated locally.
Most of the time the output precision will be so low as to show
significant banding in dark areas of the image.
png_set_expand_16(pp);
png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
This is a somewhat more realistic Jim Blinn inspired approach. PNG files
are assumed to have the sRGB encoding if not marked with a gamma value and
the output is always 16 bits per component. This permits accurate scaling
and processing of the data. If you know that your input PNG files were
generated locally you might need to replace PNG_DEFAULT_sRGB with the
correct value for your system.
png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
src/Source/LibPNG/libpng.3 view on Meta::CPAN
must always be converted to at least 8-bit format. (Even though low bit depth
grayscale images can't have an alpha channel they can have a transparent
color!)
You set the transforms you need later, either as flags to the high level
interface or libpng API calls for the low level interface. For reference the
settings and API calls required are:
8-bit values:
PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
png_set_expand(png_ptr); png_set_scale_16(png_ptr);
If you must get exactly the same inaccurate results
produced by default in versions prior to libpng-1.5.4,
use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
instead.
16-bit values:
PNG_TRANSFORM_EXPAND_16
png_set_expand_16(png_ptr);
In either case palette image data will be expanded to RGB. If you just want
color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
to the list.
Calling png_set_background before the PNG file header is read will not work
prior to libpng-1.5.4. Because the failure may result in unexpected warnings or
errors it is therefore much safer to call png_set_background after the head has
been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be
used with the high level interface.
.SS The high-level read interface
src/Source/LibPNG/libpng.3 view on Meta::CPAN
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to
8-bit accurately
PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to
8-bit less accurately
PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_EXPAND Perform set_expand()
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
src/Source/LibPNG/libpng.3 view on Meta::CPAN
x and y are 0] if the data is not present or if the
chunk is present but the unit is the pixel. The
remark about inexact inch conversions applies here
as well, because a value in inches can't always be
converted to microns and back without some loss
of precision.
For more information, see the
PNG specification for chunk contents. Be careful with trusting
rowbytes, as some of the transformations could increase the space
needed to hold a row (expand, filler, gray_to_rgb, etc.).
See png_read_update_info(), below.
A quick word about text_ptr and num_text. PNG stores comments in
keyword/text pairs, one pair per chunk, with no limit on the number
of text chunks, and a 2^31 byte limit on their size. While there are
suggested keywords, there is no requirement to restrict the use to these
strings. It is strongly suggested that keywords and text be sensible
to humans (that's the point), so don't use abbreviations. Non-printing
symbols are not allowed. See the PNG specification for more details.
There is also no requirement to have text after the keyword.
src/Source/LibPNG/libpng.3 view on Meta::CPAN
Transformations you request are ignored if they don't have any meaning for a
particular input data format. However some transformations can have an effect
as a result of a previous transformation. If you specify a contradictory set of
transformations, for example both adding and removing the alpha channel, you
cannot predict the final result.
The color used for the transparency values should be supplied in the same
format/depth as the current image data. It is stored in the same format/depth
as the image data in a tRNS chunk, so this is what libpng expects for this data.
The color used for the background value depends on the need_expand argument as
described below.
Data will be decoded into the supplied row buffers packed into bytes
unless the library has been told to transform it into another format.
For example, 4 bit/pixel paletted or grayscale data will be returned
2 pixels/byte with the leftmost pixel in the high-order bits of the
byte, unless png_set_packing() is called. 8-bit RGB data will be stored
in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
is called to insert filler bytes, either before or after each RGB triplet.
16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
src/Source/LibPNG/libpng.3 view on Meta::CPAN
grayscale images with bit depths of 2 or 4 or if there is a multiple-image
viewing application that wishes to treat all images in the same way.
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
if (png_get_valid(png_ptr, info_ptr,
PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY &&
bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
The first two functions are actually aliases for png_set_expand(), added
in libpng version 1.0.4, with the function names expanded to improve code
readability. In some future version they may actually do different
things.
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
added. It expands the sample depth without changing tRNS to alpha.
As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as
png_set_expand(); however, the resultant channels have 16 bits rather than 8.
Use this when the output color or gray channels are made linear to avoid fairly
severe accuracy loss.
if (bit_depth < 16)
png_set_expand_16(png_ptr);
PNG can have files with 16 bits per channel. If you only can handle
8 bits per channel, this will strip the pixels down to 8-bit.
if (bit_depth == 16)
#if PNG_LIBPNG_VER >= 10504
png_set_scale_16(png_ptr);
#else
png_set_strip_16(png_ptr);
#endif
src/Source/LibPNG/libpng.3 view on Meta::CPAN
4O lA GBA A T T GA GT GT GA GT GT BA + GBA G
6A CA PA CA C C A T tT PA P P C CBA + BA
6O CA PBA CA C C A tT T PA P P CBA C BA +
Within the matrix,
"+" identifies entries where 'from' and 'to' are the same.
"-" means the transformation is not supported.
"." means nothing is necessary (a tRNS chunk can just be ignored).
"t" means the transformation is obtained by png_set_tRNS.
"A" means the transformation is obtained by png_set_add_alpha().
"X" means the transformation is obtained by png_set_expand().
"1" means the transformation is obtained by
png_set_expand_gray_1_2_4_to_8() (and by png_set_expand()
if there is no transparency in the original or the final
format).
"C" means the transformation is obtained by png_set_gray_to_rgb().
"G" means the transformation is obtained by png_set_rgb_to_gray().
"P" means the transformation is obtained by
png_set_expand_palette_to_rgb().
"p" means the transformation is obtained by png_set_packing().
"Q" means the transformation is obtained by png_set_quantize().
"T" means the transformation is obtained by
png_set_tRNS_to_alpha().
"B" means the transformation is obtained by
png_set_background(), or png_strip_alpha().
When an entry has multiple transforms listed all are required to cause the
right overall transformation. When two transforms are separated by a comma
either will do the job. When transforms are enclosed in [] the transform should
src/Source/LibPNG/libpng.3 view on Meta::CPAN
is the level of opacity. If you need the alpha channel in an image to
be the level of transparency instead of opacity, you can invert the
alpha channel (or the tRNS chunk data) after it's read, so that 0 is
fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
images) is fully transparent, with
png_set_invert_alpha(png_ptr);
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
they can, resulting in, for example, 8 pixels per byte for 1 bit
files. This code expands to 1 pixel per byte without changing the
values of the pixels:
if (bit_depth < 8)
png_set_packing(png_ptr);
PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
stored in a PNG image have been "scaled" or "shifted" up to the next
higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
to 8 bits/sample in the range [0, 255]). However, it is also possible
to convert the PNG pixel data back to the original bit depth of the
src/Source/LibPNG/libpng.3 view on Meta::CPAN
if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
png_set_shift(png_ptr, sig_bit);
PNG files store 3-color pixels in red, green, blue order. This code
changes the storage of the pixels to blue, green, red:
if (color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA)
png_set_bgr(png_ptr);
PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
into 4 or 8 bytes for windowing systems that need them in this format:
if (color_type == PNG_COLOR_TYPE_RGB)
png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
where "filler" is the 8 or 16-bit number to fill with, and the location is
either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
you want the filler before the RGB or after. This transformation
does not affect images that already have full alpha channels. To add an
opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
src/Source/LibPNG/libpng.3 view on Meta::CPAN
composite images with alpha or simple transparency against the supplied
background color. For compatibility with versions of libpng earlier than
libpng-1.5.4 it is recommended that you call the function after reading the file
header, even if you don't want to use the color in a bKGD chunk, if one exists.
If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
you may use this color, or supply another color more suitable for
the current display (e.g., the background color from a web page). You
need to tell libpng how the color is represented, both the format of the
component values in the color (the number of bits) and the gamma encoding of the
color. The function takes two arguments, background_gamma_mode and need_expand
to convey this information; however, only two combinations are likely to be
useful:
png_color_16 my_background;
png_color_16p image_background;
if (png_get_bKGD(png_ptr, info_ptr, &image_background))
png_set_background(png_ptr, image_background,
PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
else
png_set_background(png_ptr, &my_background,
PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
The second call was described above - my_background is in the format of the
final, display, output produced by libpng. Because you now know the format of
the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
output and to retain palette images (the palette colors will be modified
appropriately and the tRNS chunk removed.) However, if you are doing this,
take great care not to ask for transformations without checking first that
they apply!
In the first call the background color has the original bit depth and color type
src/Source/LibPNG/libpng.3 view on Meta::CPAN
get somewhat harder. The only current (PNG Specification version 1.2)
interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7);
a somewhat complicated 2D interlace scheme, known as Adam7, that
breaks down an image into seven smaller images of varying size, based
on an 8x8 grid. This number is defined (from libpng 1.5) as
PNG_INTERLACE_ADAM7_PASSES in png.h
libpng can fill out those images or it can give them to you "as is".
It is almost always better to have libpng handle the interlacing for you.
If you want the images filled out, there are two ways to do that. The one
mentioned in the PNG specification is to expand each pixel to cover
those pixels that have not been read yet (the "rectangle" method).
This results in a blocky image for the first pass, which gradually
smooths out as more pixels are read. The other method is the "sparkle"
method, where pixels are drawn only in their final locations, with the
rest of the image remaining whatever colors they were initialized to
before the start of the read. The first method usually looks better,
but tends to be slower, as there are more pixels to put in the rows.
If, as is likely, you want libpng to expand the images, call this before
calling png_start_read_image() or png_read_update_info():
if (interlace_type == PNG_INTERLACE_ADAM7)
number_of_passes
= png_set_interlace_handling(png_ptr);
This will return the number of passes needed. Currently, this is seven,
but may change if another interlace type is added. This function can be
called even if the file is not interlaced, where it will return one pass.
You then need to read the whole image 'number_of_passes' times. Each time
src/Source/LibPNG/libpng.3 view on Meta::CPAN
png_debug1(level, message, p1)
png_debug2(level, message, p1, p2)
in which "level" is compared to PNG_DEBUG to decide whether to print
the message, "message" is the formatted string to be printed,
and p1 and p2 are parameters that are to be embedded in the string
according to printf-style formatting directives. For example,
png_debug1(2, "foo=%d", foo);
is expanded to
if (PNG_DEBUG > 2)
fprintf(PNG_DEBUG_FILE, "foo=%d\en", foo);
When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
can still use PNG_DEBUG to control your own debugging:
#ifdef PNG_DEBUG
fprintf(stderr, ...
#endif
src/Source/LibPNG/libpng.3 view on Meta::CPAN
The png_malloc_warn() function was added at libpng-1.2.3. This issues
a png_warning and returns NULL instead of aborting when it fails to
acquire the requested memory allocation.
Support for setting user limits on image width and height was enabled
by default. The functions png_set_user_limits(), png_get_user_width_max(),
and png_get_user_height_max() were added at libpng-1.2.6.
The png_set_add_alpha() function was added at libpng-1.2.7.
The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9.
Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the
tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is
deprecated.
A number of macro definitions in support of runtime selection of
assembler code features (especially Intel MMX code support) were
added at libpng-1.2.0:
PNG_ASM_FLAG_MMX_SUPPORT_COMPILED
PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
src/Source/LibPNG/libpng.3 view on Meta::CPAN
deprecated since libpng-1.0.16 and libpng-1.2.6.
The function
png_check_sig(sig, num)
was replaced with
!png_sig_cmp(sig, 0, num)
It has been deprecated since libpng-0.90.
The function
png_set_gray_1_2_4_to_8()
which also expands tRNS to alpha was replaced with
png_set_expand_gray_1_2_4_to_8()
which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
Private libpng prototypes and macro definitions were moved from
png.h and pngconf.h into a new pngpriv.h header file.
Functions png_set_benign_errors(), png_benign_error(), and
png_chunk_benign_error() were added.
src/Source/LibPNG/libpng.3 view on Meta::CPAN
png_set_mmx_thresholds(), png_get_asm_flags(),
png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
png_set_asm_flags(), and png_mmx_supported()
We removed the obsolete png_check_sig(), png_memcpy_check(), and
png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(),
and memset(), respectively.
The function png_set_gray_1_2_4_to_8() was removed. It has been
deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
png_set_expand_gray_1_2_4_to_8() because the former function also
expanded any tRNS chunk to an alpha channel.
Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32
were added and are used by default instead of the corresponding
functions. Unfortunately,
from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
function) incorrectly returned a value of type png_uint_32.
We changed the prototype for png_malloc() from
png_malloc(png_structp png_ptr, png_uint_32 size)
to
src/Source/LibPNG/png.h view on Meta::CPAN
/* Convert from a struct tm to png_time */
PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
const struct tm * ttime));
/* Convert from time_t to png_time. Uses gmtime() */
PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
#endif /* CONVERT_tIME */
#ifdef PNG_READ_EXPAND_SUPPORTED
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
#endif
#ifdef PNG_READ_EXPAND_16_SUPPORTED
/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
* of a tRNS chunk if present.
*/
PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
#endif
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
/* Use blue, green, red order for pixels. */
PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
#endif
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
/* Expand the grayscale to 24-bit RGB if necessary. */
PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
src/Source/LibPNG/png.h view on Meta::CPAN
* early Mac systems behaved.
*
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
* This is the classic Jim Blinn approach and will work in academic
* environments where everything is done by the book. It has the shortcoming
* of assuming that input PNG data with no gamma information is linear - this
* is unlikely to be correct unless the PNG files where generated locally.
* Most of the time the output precision will be so low as to show
* significant banding in dark areas of the image.
*
* png_set_expand_16(pp);
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
* This is a somewhat more realistic Jim Blinn inspired approach. PNG files
* are assumed to have the sRGB encoding if not marked with a gamma value and
* the output is always 16 bits per component. This permits accurate scaling
* and processing of the data. If you know that your input PNG files were
* generated locally you might need to replace PNG_DEFAULT_sRGB with the
* correct value for your system.
*
* png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
* If you just need to composite the PNG image onto an existing background
src/Source/LibPNG/png.h view on Meta::CPAN
#endif
#ifdef PNG_READ_BACKGROUND_SUPPORTED
/* Handle alpha and tRNS by replacing with a background color. Prior to
* libpng-1.5.4 this API must not be called before the PNG file header has been
* read. Doing so will result in unexpected behavior and possible warnings or
* errors if the PNG file contains a bKGD chunk.
*/
PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
png_const_color_16p background_color, int background_gamma_code,
int need_expand, double background_gamma))
PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
png_const_color_16p background_color, int background_gamma_code,
int need_expand, png_fixed_point background_gamma))
#endif
#ifdef PNG_READ_BACKGROUND_SUPPORTED
# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
# define PNG_BACKGROUND_GAMMA_SCREEN 1
# define PNG_BACKGROUND_GAMMA_FILE 2
# define PNG_BACKGROUND_GAMMA_UNIQUE 3
#endif
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
/* Scale a 16-bit depth file down to 8-bit, accurately. */
src/Source/LibPNG/pngdebug.h view on Meta::CPAN
/* Define PNG_DEBUG at compile time for debugging information. Higher
* numbers for PNG_DEBUG mean more debugging information. This has
* only been added since version 0.95 so it is not implemented throughout
* libpng yet, but more support will be added as needed.
*
* png_debug[1-2]?(level, message ,arg{0-2})
* Expands to a statement (either a simple expression or a compound
* do..while(0) statement) that outputs a message with parameter
* substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG
* is undefined, 0 or 1 every png_debug expands to a simple expression
* (actually ((void)0)).
*
* level: level of detail of message, starting at 0. A level 'n'
* message is preceded by 'n' 3-space indentations (not implemented
* on Microsoft compilers unless PNG_DEBUG_FILE is also
* defined, to allow debug DLL compilation with no standard IO).
* message: a printf(3) style text string. A trailing '\n' is added
* to the message.
* arg: 0 to 2 arguments for printf(3) style substitution in message.
*/
src/Source/LibPNG/pngpriv.h view on Meta::CPAN
*/
#ifndef PNG_USE_COMPILE_TIME_MASKS
# define PNG_USE_COMPILE_TIME_MASKS 1
#endif
PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
png_bytep row, int display),PNG_EMPTY);
#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Expand an interlaced row: the 'row_info' describes the pass data that has
* been read in and must correspond to the pixels in 'row', the pixels are
* expanded (moved apart) in 'row' to match the final layout, when doing this
* the pixels are *replicated* to the intervening space. This is essential for
* the correct operation of png_combine_row, above.
*/
PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
#endif
/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
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