billd@celerity.uucp (Bill Davidson) (06/05/89)
First I'd like to thank all the people who sent me info about X Terminals. Many people sent me things. My mailbox runneth over. I can probably send the stuff to a few people who ask for it but if I get over about 20 queries I won't do it anymore (maybe I'll post it but Paul Anderson already seems to be doing that occasionally). Anyway, those of you who also read comp.graphics may know that I've been involved in a discussion about color quantization. So far, my quantizer only puts out sun rasterfiles. I'd like to change to X as my working environment soon. I wanted to make X bitmap files with 8-bit color for the 3/60C we have here but I can't seem to find anything for color bitmaps. The 2-color bitmap files are straightforward. They're even easy to write without the X library functions. I found XWDFile.h and xwd. That's a program and not a library function (I think ???). Is there a way to store and retrieve arbitrary color bitmaps in files? I would think that I just can't find it in the books that I have. (Dare I say it: "It must be there" :-). Since the whole point of having a "smart" quantizer is to choose the best possible colormap for the image, I need to be able to store the colormap in the file and have the display program try to set the colormap to the one specified in the file (and, of course, restore it after it's done). --Bill (wannabegraphicsguru) Davidson Bill Davidson ...!{ucsd,sdsu,fpssun,cogen,chip,photon}!celerity!billd
robertw@hpcvlx.HP.COM (Robert B. Williams) (06/07/89)
As usual our dumb mailer can't find your address: >without the X library functions. I found XWDFile.h and xwd. >That's a program and not a library function (I think ???). Right, xwd is a client. It has a companion client xwud which will undump the file xwd writes. The R3 version (from HP anyway) will convert the colors it finds in the included colormap (see XWDFile.h) to a set of colors in a colormap matching the target visual. >Is there a way to store and retrieve arbitrary color bitmaps >in files? No such thing as a color bitmap. If its more than just on or off its a pixmap. They aren't the same, and the xlib tools for handling them aren't the same. (See Pgming Xlib 6.7) >the colormap in the file and have the display program try to >set the colormap to the one specified in the file (and, of >course, restore it after it's done). Exactly what xwud does. Of course its the window manager that actually installs the colormap, but xwud defines one from the data in the file. >--Bill (wannabegraphicsguru) Davidson Robert Williams robertw@hp-pcd.HP.COM 503-750-2818, Corvallis Workstation Operation