Jukka, Yes, I've written the Python script to do this. If you're willing to install Rasterio (which is GDAL and underneath, but new bindings and not osgeo.gdal) you can use its rio-shapes command (based on GDAL's polygonizer):
https://github.com/mapbox/rasterio/blob/master/docs/cli.rst#shapes The script's entry point is at https://github.com/mapbox/rasterio/blob/master/rasterio/rio/features.py#L197. You're welcome to port it to GDAL's Python bindings; swapping out rasterio and swapping in osgeo.gdal wouldn't be terribly hard. On Tue, Oct 13, 2015 at 5:19 AM, Jukka Rahkonen < [email protected]> wrote: > 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. > I > guess that it would work but it feels a bit complicated. Is there any more > direct way for doing this task with GDAL? I bet that at least someone has > written a python script for it because the need is so obvious. > > -Jukka Rahkonen- > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Sean Gillies
_______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
