minich@d.cs.okstate.edu (Robert Minich) (09/25/90)
by rca@cs.brown.edu (Ronald C.F. Antony): | (Izumi Ohzawa) writes: |>How about LUTs (Color lookup tables)? Do they exists on NeXTdimension |>boards? | | Can you tell me what colors you want to look up that 24-bit color does | not bring to a screen directly without a look-up? Believe it or not, there are plenty of legit reasons for CLUTs. The most interesting is probably CLUT animation. I 'spose you might be able to do something similar with the NeXTdimension and LOTS of computation, but it's a whole lot easier to just twiddle a 256x24 bit table. Seeing as visualization is an up and coming area, I am surprised CLUTs aren't available. Also, having 4096 colors is great, but you can get very good results with 256 colors that YOU get to choose. Perhaps I want to do grey scale with more than 16 shades without dithering. If you want to argue that sharing a CLUT can't be done, just look at the Mac. This is one thing Apple has done very well. If you don't care about CLUTs, you don't have to. But those who really need them can have them and still share with other programs. (Of course, total hogs in the foreground can affect background windows adversely, but at least they have the chance.) BTW, anyone have a phone # or something where I can get some info/brochures, etc. from NeXT? The people in charge of student discounts here hardly know what their pushing and I doubt they'll know anything. (ie, how can I get a student discount w/out my school acting as middleman?) -- |_ /| | Robert Minich | |\'o.O' | Oklahoma State University| A fanatic is one who sticks to |=(___)= | minich@d.cs.okstate.edu | his guns -- whether they are | U | - Ackphtth | loaded or not.
glenn@heaven.woodside.ca.us (Glenn Reid) (09/26/90)
In article <1990Sep25.060147.6502@d.cs.okstate.edu> minich@d.cs.okstate.edu (Robert Minich) writes: >by rca@cs.brown.edu (Ronald C.F. Antony): >| (Izumi Ohzawa) writes: >|>How about LUTs (Color lookup tables)? Do they exists on NeXTdimension >|>boards? >| >| Can you tell me what colors you want to look up that 24-bit color does >| not bring to a screen directly without a look-up? > > Believe it or not, there are plenty of legit reasons for CLUTs. The most >interesting is probably CLUT animation. I 'spose you might be able to >do something similar with the NeXTdimension and LOTS of computation, but it's a >whole lot easier to just twiddle a 256x24 bit table. Seeing as visualization is >an up and coming area, I am surprised CLUTs aren't available. Color lookup tables are device-dependent. If you diddle the color lookup table and the window moves so that half of it is on a black-and-white monitor, then what happens? The beauty of the PostScript indirection is that it completely isolates you from the display, which means that programs run flawlessly on any display, even if you wrote it for 2-bit grayscale and then they came out with a 32-bit color system. Not even a recompile. Animation can be nice, but there are other ways to animate that are less device-dependent. Glenn -- Glenn Reid RightBrain Software glenn@heaven.woodside.ca.us PostScript/NeXT developers ..{adobe,next}!heaven!glenn 415-851-1785