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#32 Consistant image color display with CMYK images
open
nobody
None
5
2012-10-31
2010-09-04
Anonymous
No
It seems there are some issues with the color display of CMYK images embedded with ICC profile, see attached RGB and CMYK testing cases (files uploaded at: http://drop.io/ts3thoc6759 ) created by Photoshop CS2.
If I compare the CMYK image displays with RGB displays, I can see some big differences, for instance, with CMYK images I can see the dark-green color shows as light-green.
The Windows Picture and Fax Viewer seems provides better consistent displays with both CMYK and RGB images, how can we get a acceptable color display fidelity with CMYK image by using FreeImage?
Discussion
Anonymous
Boy, this is complex topic.
For starters, real/perfect CMYK is achieved only trough some color management solution/ library (like LittleCMS) using both image pixel values and embeded profile.
If you load and display CMYK image using straight FreeImage you will NOT get the same result as, say Photoshop or (the latest versions of) MS Viewer.
HOWEVER if you save it again in cmyk (assuming it is loaded as such) the resulting file WILL be consistent with the starting file (in PS both will look the same color-wise). This is because the profile, though unused is preserved in the file upon loading and saving.
As far as I can see this bug is invalid unless you provide more info about a specific problem.
BTW the "problem" is not FreeImage specific, many viewers, including IrfanView, older MS Viewer (XP), older ACDSee etc, do not manage colors, and if you open your image there it will look like the one loaded with FI.