Re: [gdal-dev] dissolve shapefiles

2010-05-04 Thread Chaitanya kumar CH
Thomas, I would start by creating a colour table with each group containing the same shade of grey. This will ease the polygonization by avoiding duplicates. There will be three or four (RGB/RGBA) bands from the colour table but you can just consider one band during polygonization. On Tue, May 4

[gdal-dev] dissolve shapefiles

2010-05-04 Thread Thomas Unternaehrer
Hello, I try to get a dissolved shapefile out of a large raster file (Erdas img) using Python. The raster file contains values from lets say 1 to 100. What I need is a shapefile that contains just five groups where 1-20 get the value 1, 21-40 the value 2 and so on. What I've done so far are the f