Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!decwrl!mcnc!ecsgate!ecsvax!jfreem From: jfreem@uncecs.edu (Joe Freeman) Newsgroups: comp.sys.next Subject: Re: Colour Palette on a ColorStation Message-ID: <1991Apr21.134044.28646@uncecs.edu> Date: 21 Apr 91 13:40:44 GMT References: <32370001@hpcuhe.cup.hp.com> Distribution: na Organization: UNC Educational Computing Service Lines: 29 You always wonder, when replying to a message posted from a competing company, whether they have a machine or are doing corporate research. The Color Lookup Table (CLT) question is actually a two part question. 1) Does the NeXTStation Color use a CLT 2) Does the user have access to it. The NSC is a 12 bit display that can do 4096 simul. colors (4 bits rgb). The system software has postscript interpolate for all color values not in the base palette. This allows smooth blending from one color in the CLT to another. A user just asks for a color and the system returns closest. The whole idea is to get nice color, avoid hardware depend. and stop the flashing window syndrome. You know, where you go to some workstation, set the colors for one widnow and all the others change colors because they lost their colors in the CLT. The actual colors on the display are created using RAMDACs with more than 4 bit resolution. Extra bits are used for gamma correction, compensation for non linearity in the displays. The CLT is not accessable by users or their programs. Animation should probably be done with compositing. (I think the above information is correct. But, who knows.) -- Joe Freeman jfreem@uncecs.edu The opinions espressed here are my own and are not shared by my employer or anyone else I know of. Flames can be mailed to me or routed to /dev/null.