Hi,
I've been using GRASS 4.1 and I'm experiencing troubles with r.tiff
-programs. That is, when I have generated a TIFF-file with
LZW-compression, some of these files are corrupt (I have predefined
regions, and these corrupt files are always on the same regions). For
example, when I'm trying to import such file to CorelDraw 3.0 (Unix version),
I get message 'Unexpected end of file'. FrameMaker doesn't give any messages,
it just crashes. Although, XV 2.2 can read these files without problems. If I
use PackBits-compression, files are OK, but they are some 50% larger. Has
anyone experienced these troubles and is there a update available (r.tiff
I've been using is from update package #4 from ftp.cerl.army.mil).
Petri Viitanen
Tampere City Surveying Dept.
eMail: v150340@proffa.cc.tut.fi
Petri,
Yes, I know this problem, the method I use is:
- write a ppm-file with p.map, this creates the file paint.ppm
- read this file with XV and write it as a tiff with no compression
- this tiff-file you can import in CorelDraw
I did it just this morning 
What is causing this problem, I don't know, I've looked to the files that did
not work, and the problem is somewhere at 40% of the file-length.
I hope this offers you a sollution
Elwin Koster
E.A. Koster (ekoster@let.rug.nl) wrote:
: Yes, I know this problem, the method I use is:
: - write a ppm-file with p.map, this creates the file paint.ppm
: - read this file with XV and write it as a tiff with no compression
: - this tiff-file you can import in CorelDraw
: I did it just this morning
: What is causing this problem, I don't know, I've looked to the files that did
: not work, and the problem is somewhere at 40% of the file-length.
: I hope this offers you a sollution
: Elwin Koster
Yes, it is a solution, but the problem is, using xv I can't do it
automatically, so it takes some time and effort to do. What I'm
working on are shell scripts, which would update my TIFF-maps every
time the GRASS database maps have been modified. There is,
however GRASS program tiffcp which reads TIFF files and converts
them to other TIFF formats (such as LZW -> PackBits), but if I copy
my existing TIFF files with this program into LZW, the problem
is still the same. I have considered switching to PackBits-
format, but then the files would be circa two times larger and I
have to be able to distribute these files on floppy disks.
Petri Viitanen
Tampere City Surveying Dept.
v150340@proffa.cc.tut.fi
Hello Grass Users,
We are new users and request your help in generating topo maps from
dxf imported files. We have large scale topo maps from and area of interest
that a poor grad student digitized from hard copy in Autocad format. The
DXF file import was smooth but the map is a "dumb" map with no elevation
information. Can anyone help us with procedures for the incorporation of
elevation data to the x,y locations of contour lines in the raster map file?
Thanks, "learning slowly in Kalamazoo"
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* Geology Dept. *
* Western Michigan University *
* Kalamazoo, MI 49008 *
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