0

After I set the GIMP image preferences to 32bit floating point en using Linear Light, I created a new image. Then I set the foreground colour to R=50%, G=50% en B=50% and fill a rectangle with this foreground colour. To my surprise the Colour Picker tool now shows RGB values of 0.2140 instead of 0.5000 as I would expect because I am using linear colour. 50% is 50%. Since 0.2140 is the linear colour equivalent of 0.5 in the perceptual gamma space, it seems that GIMP treated my colour setting as a perceptual gamma number and converted it to linear light. Really strange. Why does the program think I started with Linear Light in the first place?

1

AFAIK the color picker doesn't display the values, you must be talking about the pointer tool display (Edit: I stand corrected)

When you set the color to RGB(.5,.5,.5) these are gamma-corrected values. "Linear-light" is about internal values and processing.

In the color picker and the pointer tool, there are various display options. The Pixel one shows the internal values (ie, RGB(0.2122,0.2122,0.2122) for the middle-gray)., the others are gamma-corrected when it makes sense (RGB(0..255), RGB(%), HSV).

enter image description here

Another place where you have the choice between linear and gamma-corrected values is the histogram.

| improve this answer | |
  • No, I am talking about the Colour Picker tool and I have the option "Use info window" checked.. In the info window there is a drop down box where you can indeed select "Pixel", "RGB" and "RGB%" etc. – Martin Janssen Apr 26 at 14:27
  • Ah, overlooked this... but this doesn't change the rest of the answer, the display options are the same, and the "Pixel" option shows the linear values. – xenoid Apr 26 at 15:47

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.