[6.4.0-4] CMYK <=> RGB Bug

[NitroPye]

Hello all,

Been having some issues converting CMYK files to RGB. If I am missing something elementary let me know but what I am trying to do worked in an older version of IM (6.2.*).

To start here are the files I used for testing:

• http://cole.nitroy.com/Files/Temp/IM_Test/Test_CMYK.psd

• http://cole.nitroy.com/Files/Temp/IM_Te ... rofile.psd

• http://cole.nitroy.com/Files/Temp/IM_Te ... t85290.icc

• http://cole.nitroy.com/Files/Temp/IM_Test/sRGB.icc

I would then try to using convert to make these into RGB PNGs.

Code: Select all

convert Test_CMYK.psd -colorspace RGB Test_RGB.png
convert Test_CMYK_NoProfile.psd -colorspace RGB Test_RGB_NoProfile.png

The files that are then produced are goofed up color-wise. They are washed out and super bright. I choose the example image because it seems greens mess up the most. I feel like a channel is missing or something rather simple. Again, I am still not 100% certain I am not at fault and could be missing something elementary.

• http://cole.nitroy.com/Files/Temp/IM_Test/Test_RGB.png

• http://cole.nitroy.com/Files/Temp/IM_Te ... rofile.png

I then tried converting via the profile switch with the same results.

Code: Select all

convert Test_CMYK.psd -profile sRGB.icc Test_RGB.png

For one last crack at it, I assumed the PSD was at fault so I converted it to a CMYK tif then tried to convert that to a RGB png with the same whacky color results.

Please don't hesistate to ask for any other details or test files. I am running version 6.4.0-4 on a Intel Mac Pro running 10.4.

Thanks in advance.

[magick]

We got reasonable results with this command:

• convert Test_CMYK.psd -strip -profile USWebCoatedSWOP.icc -profile sRGB.icc Test_RGB.png

We are using ImageMagick 6.4.0-3. Make sure your version of ImageMagick includes support for the LCMS delegate library. Type

• identify -list configure

and check to ensure lcms is associated with the DELEGATES tag.

[NitroPye]

We got reasonable results with this command:

• convert Test_CMYK.psd -strip -profile USWebCoatedSWOP.icc -profile sRGB.icc Test_RGB.png

This works for me too. The key seems to be the -profile USWebCoatedSWOP.icc. Out of curiosity where did you come up with that particular profile? The image has a different profile embedded.

We are using ImageMagick 6.4.0-3. Make sure your version of ImageMagick includes support for the LCMS delegate library. Type

• identify -list configure

and check to ensure lcms is associated with the DELEGATES tag.

Yep lcms is associated.

Thanks again.

[anthony]

Added the above solution to IM Examples, Formats, PSD and will appear in a day or two.
http://www.imagemagick.org/Usage/formats/#psd