Dear all, I would like to flip a "plain TIFF" (no geolocation information) image with respect to either lines or columns. After several tests, I finally found out I have two ways to do it : 1) with a temporary TIFF image First create a temporary TIFF image with 3 GCPs with gdal_translate Then create the final "plain TIFF" flipped image with gdalwarp 2) with a temporary VRT image First create a temporary VRT image with 3 GCPs with gdalbuiltvrt Then create the final "plain TIFF" flipped image with gdalwarp
Both ways give the same results, although the 2nd one is more efficient with large images. However, I bumped into some weird results. Here is a small example to illustrate : 1) I create a TIFF image with 3 GCPs which simulate the identity transformation : *gdal_translate -of GTiff -gcp 0 0 0 0 -gcp 100 0 100 0 -gcp 0 100 0 100 TIF_plain.tif TIF_identity_gcp.tif* 2) I warp the intermediate image with the folowing command : *gdalwarp -of GTiff -co PROFILE=BASELINE TIF_identity_gcp.tif TIF_identity_warped.tif* Surprisingly, the final image image TIF_identity_warped.tif is flipped with respect to lines (upside-down). Did I miss something ? Thanks for your hints Philippe -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
