-1

X-Post https://www.reddit.com/r/photoshop/comments/5v4zid/issue_with_color_profiles_in_grayscale_images/ (slightly edited)

Hi everybody!

I hope the language barrier will not be noticed (feel free to point out mistakes).

I have an .psd-file created in Photoshop and I have several technical limitations for it. It is a grayscale image with 5 different grey values and no gradients or transparacy. Regardsless of any color profile (or even using none), it is not possible to me to find any setting to save the image and preserve the exact grayscale values at the moment. What seems to be right in Photoshop isn't right after parsing colors by code and/or isn't right if you look at it in another program (in my case GIMP). GIMP seems to handle those colors right everytime (while it doesn't have any color profiles assigned), so I wanted to know if there is a way to set Photoshop color profiles to anything similar?

Background information:

I can't attach any images, as they are related to my work, but you can reproduce a similar file like this:

  • New image: 512*512px; grayscale mode

  • Type: saved as *.tga-file

  • Content: areas filled only with solid colours (hard edges) (0; 81; 136; 194; 255)

Additional information:

  • Depending on the colour profile selected the colour values may vary (guess this is known to everybody who ever messed with it)
  • Without usage of any colour profile the colour values in photoshop and in GIMP (without colour profile too) are not the same (GIMP: 0; 32; 82; 156; 255)
  • I've found matching color values in both programs after setting mode from grayscale to RGB and saving in Photoshop, but this leads to a bigger file size (about 3 times as big)
  • Another funny thing I noticed was when I set the image to Indexed mode (just to see what happens) --> colors are matching those I've already seen in GIMP (0; 32; 82; 156; 255).

This issue is very confusing to me and I hope somebody can shed a light into the darkness of those grayscale values :P

Cheers!

Edit: Formatting

Edit #2: Just to clearify, with "no color profile" I am refering to whether the colors are transformed automatically between color spaces. I think here (https://forums.adobe.com/thread/368889) somebody has a rather similar issue and even there, there is no working solution (I tired any suggestions without any success).

Edit #3: I've figured out a workaround: create *.psd-file in RGB mode and save as *.tga file, as this will lead to the correct color values. Re-open the file in GIMP, convert to greyscale and save again. (Wow - the only working solution I got is to use another tool... a freeware that is known as a competitor to Photoshop)

  • "Depending on the colour profile selected the colour values may vary" "the colour values in photoshop and in GIMP" - how do you find the so called values? – Euri Pinhollow Feb 21 '17 at 9:58
  • What version of Photoshop do you use? – Euri Pinhollow Feb 21 '17 at 10:03
  • Try removing profile from image before saving it (Assign profile -> No profile) if you have any. – Euri Pinhollow Feb 21 '17 at 10:16
  • @Euri - CS5 (12.1 x64) - Tried to remove profile; tried to create without profile --> seems not to help - Defined colors with "Color Picker"; read out color values with "Info" window while mouse over – user60968 Feb 21 '17 at 17:31
  • 2
    I'm voting to close this question as off-topic because it is about image editors without any apparent relevance to photography – mattdm Mar 24 '17 at 11:04
1

I cannot reproduce it with same PS version:

  • I draw distinct areas with different tones
  • I save them as both TIFF and TGA
  • I reopen them and I see same values reported as before saving the files
  • I see different values in GIMP but it must be specific to GIMP. Still same values in TIFF and TGA in GIMP

The only thing which I noticed is that you cannot set just one number from RGB in colour picker: Photoshop will mix them into grayscale in some way and unless you set all three to same value you are not getting this value as a result of filling/painting.

If this is not your problem then you have a bug.

P.S. Photoshop reports raw data values in info window, profile has nothing to do with them.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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