Is there a formula for calculating perceptual errors in gamma, eg actual display gamma vs desired target gamma?

Thanks,

Mark

Aside from Delta E and its components?

Not sure what I'm after really, just something that evaluates my gamma, either at specific points, or overall, compared to a desired gamma and gives some qualification to any adjustments I might make in an attempt to perceptually improve my overall gamma... Does that even make sense? :)

Mark

The perceptual measure of gamma points is L* aka lightness - it uses the human gamma curve to evaluate your displays gamma curve. If an individual point w.r.t. to a desired gamma curve is too light or too bright - then it will give you that perceptual error. What it cannot do is tell you what is the proper gamma for your viewing environment. The human and displays gamma are not that far apart - a happy circumstance that CRTs did not require gamma correction - they were perceptually on target already - but only in the proper environment. This is why your display should have multiple gamma options - to suit the environment.

So dL* would be something like (l2-l1)^2?

Mark

something like - errors are magnitudes in color space between two points - which means you are missing the sqrt() as well as the formulas for the two L's - which is derived from your sensors Y measure.

http://www.poynton.com/PDFs/ColorFAQ.pdf

Use 100% white measure as your normalization. This may be different for different PJ presets.