On Thu Oct 26 17:08:39 EDT 2006, [EMAIL PROTECTED] wrote: > > > the images are seperated by channel. man image(6) and draw(3). > > a 24-bit image is 1 byte each r, g, b premultiplied by the alpha channel > > which is in the fourth byte. > > > > but they are not contiguous in memory, and that is the "usual" way to > split an RGB for when you want to manipulate them
it's trivial to upconvert to 32-bit images. and then if you take every fourth byte, you have easy access to the channels. i don't see the difficulty. > > surely you'd want to undo the premultiply of the alpha http://alvyray.com/Awards/AwardsAcademy96.htm unfortunately i'm unable to currently locate the original paper referenced at the bottom of that page. > What are you going to do when you want to move the RGB into HSB or CMYK > space ? maybe there's something i'm missing, but what is the benefit to using different colorspaces? if you're using a normal computer display or printer, and you're not doing artbook printing, rgb seems to be the most straightforward representation. the screen, after all, is RGB. > Having them interleaved as RGBA, RGBA, RGBA will give you a headache > sooner or later. i fail to see this difficulty. - erik
