Le mardi 13 octobre 2015 13:19:50, Jukka Rahkonen a écrit : > Hi, > > This question appears every now and then in the gis.stackexchange and I > have been wondering about it by myself as well: How to generate a > footprint polygon of the real image data area so that the possible nodata > areas would not be included? > > I have been thinking that I could convert the original image into a new > image with alpha channel or a one-bit image with nodata=0 and yesdata=1 and > then polygonize the alpha band or the 1-bit image with gdal_polygonize.py.
You can get the image to polygonize with : gdal_translate in.tif mask.tif -b mask That should work with images with nodata or alpha channel. > I guess that it would work but it feels a bit complicated. Is there any > more direct way for doing this task with GDAL? None that I can think of. gdal_polygonize.py would possibly do a bit more work than really needed in case there are holes of nodata inside the raster and you're not interested in such holes. -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
