libjpeg API: Support reading/writing ICC profiles

This commit does the following:

-- Merges the two glueware functions (read_icc_profile() and
write_icc_profile()) from iccjpeg.c, which is contained in downstream
projects such as LCMS, Ghostscript, Mozilla, etc.  These functions were
originally intended for inclusion in libjpeg, but Tom Lane left the IJG
before that could be accomplished.  Since then, programs and libraries
that needed to embed/extract ICC profiles in JPEG files had to include
their own local copy of iccjpeg.c, which is suboptimal.

   -- The new functions were prefixed with jpeg_ and split into separate
   files for the compressor and decompressor, per the existing libjpeg
   coding standards.

   -- jpeg_write_icc_profile() was made slightly more fault-tolerant.
   It will now trigger a libjpeg error if it is called before
   jpeg_start_compress() or if it is passed NULL arguments.

   -- jpeg_read_icc_profile() was made slightly more fault-tolerant.
   It will now trigger a libjpeg error if it is called before
   jpeg_read_header() or if it is passed NULL arguments.  It will also
   now trigger libjpeg warnings if the ICC profile data is corrupt.

   -- The code comments have been wordsmithed.

   -- Note that the one-line setup_read_icc_profile() function was not
   included.  Instead, libjpeg.txt now documents the need to call
   jpeg_save_markers(cinfo, JPEG_APP0 + 2, 0xFFFF) prior to calling
   jpeg_read_header(), if jpeg_read_icc_profile() is to be used.

-- Adds documentation for the new functions to libjpeg.txt.

-- Adds an -icc switch to cjpeg and jpegtran that allows those programs
to embed an ICC profile in the JPEG files they generate.

-- Adds an -icc switch to djpeg that allows that program to extract an
ICC profile from a JPEG file while decompressing.

-- Adds appropriate unit tests for all of the above.

-- Bumps the SO_AGE of the libjpeg API library to indicate the presence
of new API functions.

Note that the licensing information was obtained from:
https://github.com/mm2/Little-CMS/issues/37#issuecomment-66450180

4 files changed, 40 insertions, 0 deletions

diff --git a/testimages/test1.icc b/testimages/test1.icc
new file mode 100644
index 00000000..d0245c81
--- /dev/null
+++ b/testimages/test1.icc
diff --git a/testimages/test1.icc.txt b/testimages/test1.icc.txt
new file mode 100644
index 00000000..57fc52f7
--- /dev/null
+++ b/testimages/test1.icc.txt
@@ -0,0 +1,20 @@
+Little CMS
+Copyright (c) 1998-2011 Marti Maria Saguer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/testimages/test2.icc b/testimages/test2.icc
new file mode 100644
index 00000000..73f1b5aa
--- /dev/null
+++ b/testimages/test2.icc
diff --git a/testimages/test2.icc.txt b/testimages/test2.icc.txt
new file mode 100644
index 00000000..57fc52f7
--- /dev/null
+++ b/testimages/test2.icc.txt
@@ -0,0 +1,20 @@
+Little CMS
+Copyright (c) 1998-2011 Marti Maria Saguer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.