[FFmpeg-trac] #9085(avcodec:reopened): JPEG: YCCK too green
FFmpeg
trac at avcodec.org
Sun Mar 21 19:52:12 EET 2021
#9085: JPEG: YCCK too green
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Reporter: Balling | Owner:
Type: defect | Status: reopened
Priority: normal | Component: avcodec
Version: git-master | Resolution:
Keywords: mjpeg cmyk | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Comment (by pdr0):
You can apply those equations, but you'd still get wrong colors unless you
convert the ICC profile CMYK to sRGB. That sample
"Channel_digital_image_CMYK_color.jpg" has a CMYK ICC profile attached
As a workaround , you can pipe imagemagick to to ffmpeg (or ffplay) , and
get close results to photoshop's CMYK to sRGB conversion. There are slight
differences in the conversion, slightly different sRGB icc profiles you
could use. For example, you could use sRGB2014.icc vs.
sRGB_v4_ICC_preference.icc vs. sRGB_ICC_v4_Appearance.icc, etc...
IM can read image sequences, but I believe it's memory bound when piped -
entire sequence must fit in RAM (or at least it used to be , not sure if
newer versions are any different), but it works. Or use batch conversion
to individual sRGB png sequence first
eg. img_000.jpg, img_001.jpg,...img_010.jpg
convert.exe "img_%03d.jpg[0-10]" -profile "USWebCoatedSWOP.icc" -profile
"sRGB2014.icc" rgb:- | ffmpeg -f rawvideo -s 500x333 -pix_fmt rgb24 -r 15
-i - -c:v utvideo -an outsequence.avi
I don't see any workarounds within ffmpeg only , and I don't see color
management coming to ffmpeg any time soon
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Ticket URL: <https://trac.ffmpeg.org/ticket/9085#comment:19>
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