On Tue, 2004-01-20 at 11:02, Supreet Sethi wrote: > Just in relation to (patent) color-depth formula by Raj Mathur.
in the words of britney "oops! i did it again!" could not resist not responding to a thread on digital color.... :-) > Color in applications are based on colormap that the application chooses > or it inherits from Xwindow. These colormaps are really indexs > maintained by the video card for colormmaping. correct. > These colomaping > algorithms vary from video card to video card. And driver takes care of > the mapping. a little more complex than that, but okay, that's the general idea. > > So there is in most cases a direct relationship between color depth used > and the video memory required but that cannot in most cases be expressed > in single formula. this is absolutely correct. for instance, my formula, though an approximation, gives a splendid idea of video-ram requirements: 1) horizontal pixels x vertical pixels x number of channels [r,g,b,alpha... (or grayscale...)] x bit-depth in bytes x video-buffer requirements calculated on frame-rate or refresh rate (with some weightage given to available processing power either on gpu or cpu) i have several variations to the formula depending on the type of workflow. once you come to video graphics, you may decide to add a huge amount of RAM, *and* a huge amount of video-RAM to get your required throughput, with a couple of special graphics cards and video cards thrown in. for instance, a few years ago (5 years +) some professionals added special photoshop hardware acceleration cards to their macs and pcs to handle stuff like blurring, sharpening, etc.... meanwhile, people who handle multi-layered composited video graphics for broadcast, with stuff like 3d surface mapping and lighting and surface textures, need to calculate their requirements using specific formulae. anyways, what is exciting is, that using thin-clients, several people could simultaneously work on such demanding tasks through a centralised high-powered server, which in turn could throw its back-end processing to a farm of renderers or grpahics processing nodes, if need be.... this part of ltsp really excites me. :-) LL [er.. what is ltsp? just check out ltsp.org] > > Another aspect of concern in terms of video memory is video caching. > Application can have a double buffered output. Some application like > ones which use OpenGL rely on the library for handling the double > buffering. In most gaming video card the library uses the video memory > rather the RAM for doing double buffering. That increase the requirement > for video RAM. > > > Sudev showed that you need only > > 2MB of video memory to run LTSP client. At this > > juncture RAJ came up with following formula to decide > > the video memory required > > (resolution * no. of bits of depth)/ 8 > > > > > Supreet > > > _______________________________________________ > ilugd mailing list > [EMAIL PROTECTED] > http://frodo.hserus.net/mailman/listinfo/ilugd > _______________________________________________ ilugd mailing list [EMAIL PROTECTED] http://frodo.hserus.net/mailman/listinfo/ilugd
