view release on metacpan or  search on metacpan

src/Source/LibJPEG/change.log  view on Meta::CPAN

feature.  A (draft) specification of the JPEG SmartScale extension is
available as a contributed document at ITU and ISO.  Revision 2 or later
of the document is required (latest document version is Revision 3).
The SmartScale extension will enable more features beside lossless resize
in future implementations, as described in the document (new compression
options).

Add sanity check in BMP reader module to avoid cjpeg crash for empty input
image (thank to Isaev Ildar of ISP RAS, Moscow, RU for reporting this error).

Add data source and destination managers for read from and write to
memory buffers.  New API functions jpeg_mem_src and jpeg_mem_dest.
Thank to Roberto Boni from Italy for the suggestion.


Version 7  27-Jun-2009
----------------------

New scaled DCTs implemented.
djpeg now supports scalings N/8 with all N from 1 to 16.
cjpeg now supports scalings 8/N with all N from 1 to 16.
Scaled DCTs with size larger than 8 are now also used for resolving the
common 2x2 chroma subsampling case without additional spatial resampling.
Separate spatial resampling for those kind of files is now only necessary
for N>8 scaling cases.
Furthermore, separate scaled DCT functions are provided for direct resolving
of the common asymmetric subsampling cases (2x1 and 1x2) without additional
spatial resampling.

cjpeg -quality option has been extended for support of separate quality
settings for luminance and chrominance (or in general, for every provided
quantization table slot).
New API function jpeg_default_qtables() and q_scale_factor array in library.

Added -nosmooth option to cjpeg, complementary to djpeg.
New variable "do_fancy_downsampling" in library, complement to fancy
upsampling.  Fancy upsampling now uses direct DCT scaling with sizes
larger than 8.  The old method is not reversible and has been removed.

Support arithmetic entropy encoding and decoding.
Added files jaricom.c, jcarith.c, jdarith.c.

Straighten the file structure:
Removed files jidctred.c, jcphuff.c, jchuff.h, jdphuff.c, jdhuff.h.

jpegtran has a new "lossless" cropping feature.

Implement -perfect option in jpegtran, new API function
jtransform_perfect_transform() in transupp. (DP 204_perfect.dpatch)

Better error messages for jpegtran fopen failure.
(DP 203_jpegtran_errmsg.dpatch)

Fix byte order issue with 16bit PPM/PGM files in rdppm.c/wrppm.c:
according to Netpbm, the de facto standard implementation of the PNM formats,
the most significant byte is first. (DP 203_rdppm.dpatch)

Add -raw option to rdjpgcom not to mangle the output.
(DP 205_rdjpgcom_raw.dpatch)

Make rdjpgcom locale aware. (DP 201_rdjpgcom_locale.dpatch)

Add extern "C" to jpeglib.h.
This avoids the need to put extern "C" { ... } around #include "jpeglib.h"
in your C++ application.  Defining the symbol DONT_USE_EXTERN_C in the
configuration prevents this. (DP 202_jpeglib.h_c++.dpatch)


Version 6b  27-Mar-1998
-----------------------

jpegtran has new features for lossless image transformations (rotation
and flipping) as well as "lossless" reduction to grayscale.

jpegtran now copies comments by default; it has a -copy switch to enable
copying all APPn blocks as well, or to suppress comments.  (Formerly it
always suppressed comments and APPn blocks.)  jpegtran now also preserves
JFIF version and resolution information.

New decompressor library feature: COM and APPn markers found in the input
file can be saved in memory for later use by the application.  (Before,
you had to code this up yourself with a custom marker processor.)

There is an unused field "void * client_data" now in compress and decompress
parameter structs; this may be useful in some applications.

JFIF version number information is now saved by the decoder and accepted by
the encoder.  jpegtran uses this to copy the source file's version number,
to ensure "jpegtran -copy all" won't create bogus files that contain JFXX
extensions but claim to be version 1.01.  Applications that generate their
own JFXX extension markers also (finally) have a supported way to cause the
encoder to emit JFIF version number 1.02.

djpeg's trace mode reports JFIF 1.02 thumbnail images as such, rather
than as unknown APP0 markers.

In -verbose mode, djpeg and rdjpgcom will try to print the contents of
APP12 markers as text.  Some digital cameras store useful text information
in APP12 markers.

Handling of truncated data streams is more robust: blocks beyond the one in
which the error occurs will be output as uniform gray, or left unchanged
if decoding a progressive JPEG.  The appearance no longer depends on the
Huffman tables being used.

Huffman tables are checked for validity much more carefully than before.

To avoid the Unisys LZW patent, djpeg's GIF output capability has been
changed to produce "uncompressed GIFs", and cjpeg's GIF input capability
has been removed altogether.  We're not happy about it either, but there
seems to be no good alternative.

The configure script now supports building libjpeg as a shared library
on many flavors of Unix (all the ones that GNU libtool knows how to
build shared libraries for).  Use "./configure --enable-shared" to
try this out.

New jconfig file and makefiles for Microsoft Visual C++ and Developer Studio.
Also, a jconfig file and a build script for Metrowerks CodeWarrior
on Apple Macintosh.  makefile.dj has been updated for DJGPP v2, and there
are miscellaneous other minor improvements in the makefiles.