[gdal-dev] how to combine overlapping rasters?

[Brian Case]

Etienne

if they overlap your limited to one of 2 options to mosaic

gdalwarp or mapserver

to get what ones are on top with gdalwarp i would imagine you would just
need to play with the order on the command line.

Brian


On Tue, 2011-12-06 at 19:59 -0200, Etienne Tourigny wrote:
> Hi all.
> 
> I am trying to combine 2 overlapping rasters into a single raster.
> Specifically, I have a raster for land cover types covering South
> America and another one for Brazil.
> 
> I want the values from the Brazil map to overlap the values from the
> South American map.
> To complicate things further, the Brazil map has some holes (no data
> inside the map), which I would like to be set from the South America
> map.
> 
> Can this be done with gdal utilities or Gis, or do I need to write a
> python script?
> I thought of doing some tricks to the Brazil map and create a band
> from which I could set nodata values in South America map, and
> then using gdalwarp (combining the modified South America map and the
> Brazil map), does that make sense?
> 
> Posted sample jpg+jpw files at
> http://www.openclimgeo.org/pub/maps/
> 
> A related question: How can I effectively mask (mark as nodata) raster
> pixels inside a polygon?  For example, I would like to set the pixels
> of the South American map to nodata inside the political boundaries of
> Brazil, from a shapefile.
> This is the *reverse* of clipping a raster based on a a polygon (like
> gdalwarp -cutline -crop_to_cutline  does)
> 
> Thanks,
> Etienne
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev