Quality control check for linearity of grayscale color

[kmurphy61]

Is your feature request related to a problem? Please describe.
I would like to check the quality of my image, and particularly my camera quality. I want to understand if my black to grey values in a color card are linear (good quality) or non-linear (representing an issue with image quality).

Describe the solution you'd like
I would like to make a plot of the color chip number (1 = black, 5 = white) on the X axis, and the intensity on the Y axis (see image example below). I would like to show the expected values in a perfect scenario, the values before color correction, and values after color correction. I would like a warning threshold, so that if there is greater than 5% deviation from linear before color correction (default = 5%, but is a parameter than can be adjusted), a warning message will appear for the user to check camera settings or use an alternative image correction, such as a gamma or logv correction. I do not want the R, G, and B in the sample plot, just the grayscale chips.

Describe alternatives you've considered
This could be part of the color card functions, or part of the quality control subpackage.