Image Tolerance - What does the scale actually mean?

I know that when using the dynamic image generator I can set the tolerance for values between 0 and 100. What is the actual effect of this scale? Is there a way to generate images on each end of this scale so that I can identify the difference between a tolerance of 1 and a tolerance of 80.

If the tolerance is set to 80, does that mean a dynamic text image I generate match if any of the rgb values are within ± 80 of my targeted color?

(If anyone wants to know, I’m using the dynamic image generator to generate link images for a website - from simple trial and error if I set my font color to (0,0,203) and the tolerance to 80 I can find my links - but it would be nice to approach this with a bit more logic beyond trial/error.)

You are exactly correct that it means you have a that amount of ± leeway for each RGB-component. So at 80, your links will match components anywhere in the range of (0-80,0-80,123-255). There is a bit more than just bit-map comparision going on but it does refer to the RGB difference.

PS – Love the Avatar.