I am new to GRASS and just getting started. I have a scanned image of a USGS topographic map that I would like to start with and have been working through the tutorial in grass50_tutorial_en.pdf. On page 79 step "d.", second bullet it says "Change to the GRASS monitor. Here display the imported map." How is this done? I have launched "d.mon x0" in step c. run i.points as stated at the beginning of step d. and I have a blank monitor screen. Now what? Anything I have been able to think of to get a map display either just doesn't work or generates a error. It seems there is a bit of "magic" here that is not explained.
The scanned image was imported with r.in.tiff. r.in.gdal seg faults every time I run it. I have also converted the image to PNG and r.in.png blows up because it is asking specifically for libpng.so.2. The Linux installation is Mandrake 9.1 just freshly installed.
that's right. If you have another monitor open you might need
d.mon select=x0 as well..
Here display the imported map." How is this done?
g.region rast=scannedmap # zoom to the bounds of the imported map
d.rast scannedmap
(you should have imported into a XY location)
some of my old notes:
To register a TIFF:
eg NZ7624.tiff:
info from GIMP/Paint Shop Pro:
299x299 dpi
Orig Map Scale 1:60,000
256-colours
8412x12601 pixels
As per Intro to GRASS, p27:
1cm = 600m
299 dpi = 299/2.54cm = 117.72 lines/cm
Per cm, the ratio is: 600m/117.72 = 5.097m/line
Cell resolution is therefore 5.097m2.
Mind the disk space! May be hundreds of MB a piece!
r.in.tiff Easier with support file.
(i.group) Make a new map group, add new raster to that group
i.target \
i.point \
i.rectify _\/_
r.in.gdal seg
faults every time I run it. I have also converted the image to PNG and
r.in.png blows up because it is asking specifically for libpng.so.2.
hopefully someone else on the list can help you with that, as they are
things which should be fixed in GRASS.