At 3:23 PM -0600 3/12/02, Howdy-Tzi wrote: >Cole wrote: > >>I'm about to whip up a little MIAW util to convert a bunch of bitmap >>members from 32 to 16 bit. If possible, I'd like to avoid off white >>being rounded to pure. > >I'm just hacking through the first few chapters of James Newton's >book and he mentions two different dither algorithms for 16 bit >color that are undoc'd and may or may not work. > >The params are [#dither:1215] and [#dither:1969] -- the latter is >according to James a higher-quality one.
Great! I'll try that out. I wonder if [#dither:1969] is the same method as DeBabelizer's diffusion by QuickDraw? >However he also points out that there is no RGB ( 255, 255, 255 ) in >16-bit color; the highest white value is actually rgb ( 248, 248, >248 ). > >I guess the thing to do is try a plain vanilla dither from 32 to 16 >in different situations and see if you *ever* get a conversion to >solid white. I bet you don't based on what I've been discovering... So far I'm having pretty good luck with copyPixels, but I'm beginning to suspect that the images were originally 16 bit. I'll have to try some better test data. Thanks again, Cole [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
