Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!pacbell.com!att!ucbvax!UCBVAX.BERKELEY.EDU!"Dan Karron From: Dan Karron@UCBVAX.BERKELEY.EDU Newsgroups: comp.sys.sgi Subject: Re: iopen arguments Message-ID: <9103311837.AA16138@karron.med.nyu.edu> Date: 31 Mar 91 18:37:41 GMT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: karron@cmcl2.nyu.edu Organization: The Internet Lines: 47 Thanks for your response. I have been using my hacks for months and months, but it was only recently that I thought I might check with you or the net for what is the ``right way'' to do this. Since the sgi machines (for the moment) have 8 bit dac's, any reference to more than 1 bytes per pixel must be a color index reference. If sgi is planning to use more than 8 bits gray scale, great ! I will keep that in mind in my software. My correspondence with Forest Baskett indicate that that will not happen in the near term, but X does use more than 8 bit pixels although it compresses the range on the fly. My problem is that for simple 2d image manipulation I rely on, or build on your code. I keep pixels in ipaste format so that I, and the sales demo programs will run with native data . Now I read ipaste files and need the entire 12 bit depth for 3d reconstruction and window the 8 bits resolution into the 12 bit depth. I got a note from davie blythe about this, and this is what I will do, and if this is what you reccommend, fine. ------------------------------------------------------------------------------- I frequently use images with 12 bit pixels which are displayed using the colour lookup table (aka cmode()). This is what I pass to iopen() and I also call setcolormap() afterwards to indicate it is a `SCREEN' image image = iopen(argv[2],"w",RLE(2),2,xsize,ysize,1); isetcolormap(image,CM_SCREEN); I have seen other code with zsize set to 0, so I doubt it matters. Most of the imgtools work with SCREEN images (i.e. assemble,izoom,iflip,... but may not set the output type to SCREEN properly (which you can fix in the source code or use the command 'iset SCREEN file'). Some of the commands, however, do not work with all SCREEN files e.g., hist ... david blythe ontario centre for large scale computation drb@clsc.utoronto.ca Cheers! dan. | karron@nyu.edu (e-mail alias ) Dan Karron, Research Associate | | Phone: 212 263 5210 Fax: 212 263 7190 New York University Medical Center | | 560 First Avenue Digital Pager <1> (212) 397 9330 | | New York, New York 10016 <2> 10896 <3> |