Le jeudi 13 février 2014 17:03:11, Gregory, Matthew a écrit : > Hi Eli, > > Eli Adam wrote: > > <[email protected]> wrote: > > > Hi all, > > > > > > We have been using -tap as a command-line argument to gdalwarp to > > > force pixels to be aligned with the origin (0,0) in the output > > > > coordinate system. > > > > > We now have a situation where we want to specify a different 'snap' > > > coordinate for pixel alignment (e.g. (15,15)). Is there a simple > > > mechanism for specifying this within gdalwarp that I'm overlooking? > > > > Not exactly sure what you mean. But you might try using -tr as well. > > I'm not exactly sure of how -tr and -tap relate from the docs, > > > > -tr xres yres:set output file resolution (in target georeferenced units) > > -tap:(GDAL >= 1.8.0) (target aligned pixels) align the coordinates of > > the extent of the output file to the values of the -tr, such that the > > aligned extent includes the minimum extent. > > Thanks for your help. I left out some key information from my initial post > which was that I am also passing -tr 30 30 as an argument to gdalwarp. > When using -tap along with this, the pixels are aligned with the origin. > What I really want is for the 30m pixels to have a corner at (15, 15) in > the output projection. > > The only way I've figured out how to do this is to first find the projected > extents of the output image (via osr in python), modify these extents to > snap to my desired snap window and then use the -te command line option to > explicitly set the extent. > > I was just looking for an obvious way to specify this just using gdalwarp > command line options.
Your method is the best method I can think of currently. > > thanks, matt > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
