I have an input jpg image (sat thumbnail) and I know a number of gcps for this image. I want to reproject the jpg to have a north up image. This is what I do:
./gdal_translate -of GTiff -a_srs EPSG:4326 -gcp pixel line lon lat -gcp pixel line lon lat ... etc... myinputfile.jpg temp.gtif
./gdalwarp -t_srs EPSG:4326 -r near temp.gtif myoutputfile.tif
The result is "almost" correct, although I do get some strangest behaviours sometime, eg the image folds on itself, etc... very artistic but not good for a GIS application! If anybody can see anything wrong with the way I proceed or has a better idea, please advise!
Alright, it is working now. I believe the "weird" results were down to the fact I used a temporary file that was not deleted between gdal calls. As soon as I had the temp file removed (rm temp.gtif) between calls the results were fully normal.