Bodick@CIS.UPENN.EDU (Andre Marquis) (10/02/87)
I wish to display 24-bit images using NeWS. The following code works on an 8-bit (color) display, but not on a 1-bit display (much is copied from $NEWSHOME/bin/showimage): /win framebuffer /new DefaultWindow send def 0 0 480 512 /reshape win send %Image is 512x480 pixels (/usr/NeWS/smi/mona-smile-hires.im8) readcanvas /pic exch def win begin /PaintClient { ClientCanvas setcanvas clippath pathbbox scale pop pop pic imagecanvas } def end /map win send If "mona-smile.im8" (8-bit image) is substituted for "mona-smile-hires.im8" (24-bit image), the above code works. I assume someone just didn't have time to cover all the possibilities. So, 24->8 works, 8->1 works and 24->1 doesn't work. Is there going to be future support for 16 or 32 bit images? After all, pixrects supports 16 and 32 bits, but not 24. (24 can be faked, but I had to write my own pr_get and pr_put to do it. How did you people at Sun make the *-hires files?) The dithering routines do an excellent job. Now, is there any way to the the pixel data off the canvas and in to a file once it has been dithered? I want to be able to pull images up quickly in sequence without having to retain all the canvases. (Think of a remote machine with prodigious storage and a server with little.) Can NeWS recognize that an image has the same depth as the display, the same colormap and the same dimensions as the canvas so something like a pr_load directly to screen memory will work? Currently I capture a 24-bit image, compress it to 8-bits using error diffusion, save that to a file and then display the final result on the screen under SunView with my own colormap. I would prefer to capture the 24-bit image, have NeWS dither it to its colormap and save that result. That would make image retrieval as fast as possible (on equivalent display devices). NeWS is a little show in dithering images with my colormap and the results are not perfect -- apparent resolution is lost because of the color changes. Any thoughts anyone? Andre Marquis Department of Pathology and Lab Medicine 2 Gibson Building Hospital of the University of Pennsylvania 3600 Spruce Street Philadelphia, PA 19106 (215)662-6886 bodick@cis.upenn.edu "Occasionally a pixel is a good thing."