Converting RGB to CMYK correctly?

[agamemnus]

Hello, can anyone tell me how to convert RGB to CMYK without varying color? I was able to do so manually in Photoshop, but I cannot do it in Imagemagick. I tried "-colorspace CMYK" with and without "+profile icm(/etc.)" and it is all the same: the converted image is lighter than the original.

[fmw42]

There have been a lot of posts related to this topic. Use the search feature and include the search words, RGB CMYK. To do it properly, you probably need to use a profile. But I am not an expert on this topic.

Also see:
http://www.imagemagick.org/Usage/channels/

Also certain image formats do not support CMYK. I think two are gif and png, but I that is from recall from another earlier message. So you should check on that.

[brian_jackson]

See this post: viewtopic.php?f=1&t=9227

[agamemnus]

There have been a lot of posts related to this topic. Use the search feature and include the search words, RGB CMYK. To do it properly, you probably need to use a profile. But I am not an expert on this topic.

Also see:
http://www.imagemagick.org/Usage/channels/

Also certain image formats do not support CMYK. I think two are gif and png, but I that is from recall from another earlier message. So you should check on that.

I did search, but none of the topics helped. I also tried "RGB to CMYK", but the search function just ignores "to".

The image is .JPG. JPG should work because Photoshop can do it just fine.

See this post: viewtopic.php?f=1&t=9227

Where can I get a color profile like the one Adobe Photoshop uses?

[brian_jackson]

Where can I get a color profile like the one Adobe Photoshop uses?

I've got the AdobeICCProfiles-2.0-31 rpm installed which provides quite a few ICC profiles.

I don't use Photoshop, so I couldn't really help you there, but I'm pretty sure the profiles that Adobe provides are most likely the same ones they use in their own applications.

good luck