Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
R. Bauer (r.bauer@fz-juelich.de) writes: > I found in one of the readme.txt the command: DEVICE, DECOMPOSED=0 > It will switch if the graphic card is in true color mode to an indexed > color mode of 8bit. No, I'm quite sure it didn't say that (although I can't find the reference to be sure). I think what it probably said was that setting DECOMPOSED=0 allows you to specify colors *as if* you were using the indexed color mode. In other words, you don't have to do this to get your plot in a yellow color: IDL> Plot, data, Color='00ffff'x Instead, you can do this: IDL> TVLCT, 255, 255, 0, 10 IDL> Plot, data, Color=10 > Set this keyword to 0 to cause the least-significant 8 bits of the color > index value to be interpreted as a PseudoColor index. This setting > allows users with DirectColor and TrueColor displays to use IDL programs > written for standard, PseudoColor displays without modification. I think this is a true statement, as far as it goes, although it doesn't cause you to anticipate the problems you inevitably encounter below. > I found following differences to the real 8bit graphic mode. > > 1. tvrd() did not work! > the results are very surprising me You are obviously not keeping up with the articles on my web page. ;-) Try this one: http://www.dfanning.com/tips/tvrd_16bit.html > 2. if I change the color table e.g. loadct,2 the colors on screen won't > refresh. I have to start the application again to get the result in > the new colors. Try these articles: http://www.dfanning.com/tips/colors24.html http://www.dfanning.com/tips/noxloadct.html http://www.dfanning.com/tips/24bit_color_idl51.html I am finding that I *love* to run IDL in 24-bit mode. I can have as many color tables as I like, I don't have to worry about direct graphics programs and object graphics programs working together, I get *great* color saturation, etc. The only problem is writing programs that work with color tables properly when I change the color tables. For that, you can read this article: http://www.dfanning.com/tips/identical_graphics.html Of course, my book explains all of this in even more detail. :-) Cheers, David ---------------------------------------------------------- David Fanning, Ph.D. Fanning Software Consulting E-Mail: davidf@dfanning.com Phone: 970-221-0438, Toll-Free Book Orders: 1-888-461-0155 Coyote's Guide to IDL Programming: http://www.dfanning.com/