OpenJPEG-1.3.0 pclr, cmap and cdef

[gcode-importer]

Originally reported on Google Code with ID 27

I have now made changes in jp2.c and jp2.h to handle pclr, cmap and
cdef. The files are attached as a whole.

jp2_read_colr(), jp2_read_jp2h() and jp2_decode() have been changed.

The changes are in jp2.c between 'begin INSERTION' and 'end INSERTION'.

First I inserted the necessary structures into opj_jp2_t . But then
I learned that MJ2 was unhappy with this decision. I have now made
the structures static in jp2.c . I suppose they can be inserted
into the opj_image_t, if static structures are unwanted.

It seems that I completely misunderstand the channel model of JP2.
Section I.5.3.6 in Part 1 suggest that there may be multiple opacity
channels. Until now I understood that there is either no channel or 
one channel for opacity, i.e. transparency.

I have found the four test files in the fdis_j2kp4files.zip archives.

testfiles_jp2/file2.jp2 contains a 'cdef' box:
===============================================
[0]cn(0) typ(0) asoc(3)
[1]cn(1) typ(0) asoc(2)
[2]cn(2) typ(0) asoc(1)

The color space is sYCC. Ignoring 'cdef' means: using the wrong color
for Y resp. Cr. The image had false colors. It looked ugly. Now it
looks nice.

testfiles_jp2/file9.jp2 contains a 'pclr' and a 'cmap' box:
===========================================================
The color space is sRGB. The image has one component: the index channel.
Ignoring 'pclr' and 'cmap' means: using the index channel as the color
channel. The result looked ugly. Now it looks nice.

testfiles_jp2/file5.jp2 and testfiles_jp2/file7.jp2 both contain an
===================================================
ICC Profile. I have written a simple program that reads the profile
correctly. But I do not know how to include the profile into jp2.c :
WHERE/WHEN shall the profile be read, WHO shall use the values, ...

Nice enterprise for someone else.

winfried

Reported by szukw000 on 2010-05-12 13:11:27

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- _Attachment: [jp2.c.7z](https://storage.googleapis.com/google-code-attachments/openjpeg/issue-27/comment-0/jp2.c.7z)_ - _Attachment: [jp2.h.7z](https://storage.googleapis.com/google-code-attachments/openjpeg/issue-27/comment-0/jp2.h.7z)_

[gcode-importer]

I had first made a 'proposal' (issue 25) for a change in jp2.c/jp2.h . As nobody
answered, I made a change (see above).  Then I realized that Marek Mauder sent
a patch to the LIST (date:26.01.2010). I want to point to the fact that Marek
made the same mistake as I did first: changing 'opj_jp2_t'. THIS WILL BREAK MJ2.

winfried 

Reported by szukw000 on 2010-05-14 07:35:02

[gcode-importer]

Reported by malaterre on 2014-02-25 15:42:26

• Labels added: Priority-Low
• Labels removed: Priority-Medium

[gcode-importer]

closing current issue, please follow issue 82

Reported by malaterre on 2014-02-26 14:09:37

• Status changed: Duplicate
• Merged into: pclr-cmap-cdef #82