with an given .h file with RGB color, how to reset the value for color? for example, if i want to reset the value for R is 0.4, etc.? Thanks.

I’m not quite sure what you mean… can you be more specific what it is you are trying to do?

after readin an image, how to reset the color for each pixel? each pixel should contains RGB, and I want to set a specific value for each color which makes L = .3R + .6G + .2B ?


sounds very similar to a problem I discussed with a grad student just about a week ago… I would suggest trying to use scanline function to get a rgb value… then from there whatnot. Scanlines are fairly slow, but there aren’t a whole lot of other ways I know of to read values pixel by pixel