Newsgroups: info.grass.user
Path: zorro.cecer.army.mil!shapiro
From: shapiro@zorro.cecer.army.mil (Michael Shapiro)
Subject: Re: reading in a SPOT image
Message-ID: <C3I5MD.8yD@news.cecer.army.mil>
Sender: news@news.cecer.army.mil (Net.Noise owner)
Organization: US Army Corps of Engineers Construction Engineering Research Labs
References: <9302232107.AA08927@cast.uark.edu>
Date: Sun, 7 Mar 1993 04:54:13 GMT
Lines: 31
In <9302232107.AA08927@cast.uark.edu> wang@cast.uark.edu (Wang Song) writes:
I'm having problems reading a (panchromatic) spot image into grass.
Here is what I did: I created a x,y coordinate location and set the default
window so that it matches the size of the image. I placed the image file
in the cell directory and ran r.support to create additional support files
(header, cats, and colr). The problem I'm having is that whenever I try to
display the image I get an error message saying can't set color 256, and
when I try to use d.colors it tells me "filename" has more colors than the
graphics device, though I'm using a 24 bit color monitor. I can't change
the colors interactively. Why?Thanks, Magaly
The error message is a bug in the driver. Get the new XDRIVER.
Also, the XDRIVER doens't work with 24 bit visuals. You have to
set your Xserver to use a PseudoColor visual as the default. And
if you want to use d.colors you have to have a map with under 240
colors since GRASS reserves about 16 for vector colors, so that leaves
240 (256-16). If you map has more than this max (~240) colormode
float makes no sense since there aren't enough color registers available
to give each color in the map its own register in the graphics lookup table.
You can still use d.colors to modify the color table, but it cna't show
you the changes until you redisplay the map (using d.rast).
--
Michael Shapiro U.S. Army CERL
Environmental Division