Hi everyone. I have a question about greyscaling and colormaps under X. You
may say, "This is not the right newsgroup," and I would agree with you,
*except* that I have a problem with a couple applications on my FreeBSD system,
using XFree86 2.1 (X11R5), which don't show problems on machines in my
department, HP735s and Sparcs running X11R5.
Ok, here is the problem:
I have an astronomical image, in FITS format, which I can read into xv 3.00,
which has an added FITS patch. I can create a PostScript file from this,
preview it with Ghostview (at school) and print it on a laser printer. So far,
no problems. However, I can preview it on my PC with Ghostview, and the faint
backround and slightly brighter halo of the galaxy in the field will come out
fine, but at a certain point the brightness level wraps itself around to black,
as opposed to finding a saturation level at the brightest part of the colormap.
I also see this effect on my PC directly viewing the FITS file with an image
previewer called SAOimage, which I don't have a problem with at school.
I find this strange, because in all other ways, I have had no problem
compiling, installing, running, using, etc. these two programs. However, this
"wrapping" effect puzzles me. In fact, I can use both Ghostview and SAOimage,
albeit slowly, over a PPP connection with a workstation at school, and these
very same images/PS files look fine on my monitor! So, does anyone "in the
know" have a clue/suggestion/piece of wisdom/criticism for me?
Also, I don't think that this is a platform dependent problem. But, I could be
wrong (obviously). Thanks for your time.
Indiana University Astronomy