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devel/exe-misc.c  view on Meta::CPAN

  im = gdImageCreate (20, 10);

  black = gdImageColorAllocate(im, 0, 0, 0);
  white = gdImageColorAllocate(im, 255, 255, 255);

  gdImageFilledRectangle(im, 0,0, 19,9, black);
  gdImageRectangle(im, 5,5, 15,5, white);

  fp = fopen("/tmp/x.png", "wb");
  if (fp == NULL) abort();
  gdImagePng(im, fp);
  if (ferror(fp)) abort();
  if (fclose(fp) != 0) abort();

  system ("convert  -monochrome /tmp/x.png /tmp/x.xpm && cat /tmp/x.xpm");
  exit(0);
}

lib/Image/Base/GD.pm  view on Meta::CPAN

And read-only,

    xpm      with libXpm
    xbm

PNG, JPEG and XPM are available if libgd is compiled with the respective
support libraries.  GIF will be unavailable if the Perl C<GD> interface was
built with its option to disable GIF.

C<load()> auto-detects the file format and calls the corresponding
C<newFromPng()> etc.  "gd" file format differs between libgd 1.x and 2.x.
libgd 2.x could load the 1.x format, but always wrote 2.x so that's what
C<save()> here gives.  Both "gd" formats were a byte dump mainly intended
for temporary files but are unsupported in current libgd.

WBMP is a bitmap format and is treated by GD as colours black "#000000" for
0 and white "#FFFFFF" for 1.  On save, any non-black is treated as white 1
too, but not sure that's a documented feature.

=head2 Other GD Modules