Raster Line Drawing and Labelled Polygons

[gcolello at biosphere.Stanford.EDU]

Scenario: We have a line drawing outlining Stanford's Jasper Ridge  
soil areas scanned in on a Mac resulting in a PICT format image file  
(This is a black and white drawing.). The scanned drawing was edited  
in SuperPaint so that the lines are only 1 pixel thick and outline  
only closed polygons. We also have a version of this drawing in which  
we used the paint bucket in SuperPaint to colorize the polygons  
manually with 7 differnet colors (soil types). This of course still  
has the 1 pixel lines in it.

Question 1: Can Grass even import a PICT file?  If so, can Grass take  
a scanned line image and erode the lines to single pixel widths?

Question 2:  We realize that the successfully imported line drawing  
could be used as a raster overlay plane like is done in the Spearfish  
data base with Streams. However, can GRASS take any of these PICT  
images and generate a numbered polygons file like it is possible to  
do with a spectral image file? We assume the final polygon product  
should have no lines at all. This means some sort of decision process  
as to which polygon gets which pixels from bounding lines.

Any comments?

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Greg Colello
Carnegie Institution, Department of Plant Biology
Stanford University
gcolello at biosphere.stanford.edu