I have a bug with one application that does not handle negative pixel spacing values. Therefore I would like to change the negative pixel values of my images (geotif) into positive values (while keeping the georeferencing, of course.
I've tried with gdalwarp and gdal_translate but the output still remains in negative values. My workaround was to create a tfw, ten "manually" edit it to get positive Y values and changing the origin to lower left instead of upper left. However, I would like to know if there is an easier (and faster) method to achieve this. If possible using gdal.
EDIT: I don't want to flip the images : I want an output that is georeferenced with positive pixel spacing in X and Y (so the origin should be at the bottom left) but pixels mustn't move. I've tried editing the geotransform but this does not modify the row order.