On jeudi 9 mai 2019 19:31:55 CEST Quinn, Gary wrote: > I am new to Qgis. > > I have an .flt (floating point raster) file and an associated .hdr file. > I can import the .flt image file into Qgis (using Add raster layer), and > the image displays correctly. > But how do I geolocate this image using the associated .hdr file? > In other words, how do I make Qgis use the .hdr file to let me know the > lat/lon of each pixel on the display? > > Note: The .hdr file is like this: > geo points = { 1, 1, -40.212464, 146.355212, 1, 2590, > -44.006326, 145.100364, 1024, 2590, -44.252673, 146.901021, 1024, > 1, -40.442148, 148.049722} > > So I want Qgis to use this .hdr information to geolocate the image. > I have searched various info about using .flt images and geolocation but > can't find anything.
Gary, Those are ground control points in the ENVI format: https://www.harrisgeospatial.com/docs/ENVIHeaderFiles.html GDAL can write those, but not read them, hence the georeferencing is ignored. I've filed https://github.com/OSGeo/gdal/issues/1528 about that In the meantime you could use the georeferencer to add manually the ground control points. As documented, the values in geo points are a succession of pixel_x_coordinate, pixel_y_coordinate, latitude, longitude Note: you must substract 1 to pixel_x_coordinate and pixel_y_coordinate since the GDAL/QGIS convention for origin of a raster is (0,0) whereas ENVI uses (1,) Even -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user