Programmatically determine the average greyscale
hh at livecode.org
Thu Feb 18 19:46:58 EST 2016
I now saw, late -- sorry, that you are using button's showName, that is, the text colour has to be adjusted, not the pattern.
Then using a text field instead of 'showName' and setting the field's ink to "notSrcAndReverse" should do what you want (incl. nice effects).
Here's a formula for a weighted mean close to that some professional apps use when converting an image to grayLevel.
This is derived from "perception" values (note: .6 is close to goldenRatio) of the human eye:
## g = (1*r + 6*g + 3*b) div 10 for each r,g,b-pixel
used for fully opaque pixels.
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