Sign up ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Is there a way to convert a JPEG from CMYK to RGB, using Preview or any other tool built into Mac OS X?

I see I can go to Tools | Assign Profile… and select from a long list of options, including Generic CMYK Profile, but there's no RGB option.

share|improve this question

7 Answers 7

up vote 12 down vote accepted

I found three ways to do it.

  1. Open the image with ColorSync.
  2. Use the Apply ColorSync Profile to Images action in Automator.
  3. Use sips (thanks NSD) and supply the --matchTo argument. I wrote a shell script to convert an image using the Generic RGB Profile.



if [ $# -lt 1 ]; then
    cat >&2 <<EOF
    $0 filename
    $0 source-file destination-file

    Converts an image to RGB color space. The first form manipulates
    the file in-place.
    exit 1


if [ $# -lt 2 ]; then

sips \
    --matchTo '/System/Library/ColorSync/Profiles/Generic RGB Profile.icc' \
    "$SOURCE_FILE" \
share|improve this answer
The sips invocation worked for me. – Eric Rath Mar 16 '11 at 17:46

On my machine (10.6.2), two RGB profiles are offered: "Adobe RGC (1998)" and "Generic RGB Profile". Gimp (free) can do the conversion, too.

share|improve this answer
I get those options as well when I open an image that's already RGB. – Patrick McElhaney Mar 8 '10 at 13:40

share|improve this answer
Thanks. That led me to the answer, and a couple of GUI interfaces as well. – Patrick McElhaney Mar 8 '10 at 14:37

I didn't have the RGB colorsync profiles, so I imported the files into iPhoto and then exported them again. The exported photos were in RGB. Voila

share|improve this answer

For whatever reason I wasn't able to change the color mode with Preview and the Tools section. My needs my have been simpler, but I ended up just opening the image in Preview on my large external monitor and then using Skitch to take a screenshot of it. It fit my needs, it may fit yours.

share|improve this answer
+1 for the simplest solution. Thank you! Took my screen shot in OS X, but it works just the same. – Dan The Lion Oct 27 at 16:13

It's really easy. You don’t need to do any of these steps. In the Mac OS X “Preview” app, just go under Tools, Match to Profile, and under “Color Model” select RGB. The ColorSync Profile will change automatically. Save, and it’s done!

share|improve this answer
In what program? – Daniel Beck Aug 29 '12 at 17:00
"Preview". – Fabian Zeindl Aug 4 '14 at 10:25

If you have ImageMagick installed on your machine, you can do this in Terminal.

For image.jpg:

convert -colorspace RGB image.jpg newImage.jpg

newImage.jpg will be the same image in RGB space.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.