I have several hundered geotiff files. Some of them (almost all of them) have black areas (irregular) on the edges. However, these black areas are covered by some other file in the file set.
I read this post but it looks that the black in my file is not marked as NODATA (only 3 bands in the VRT file).
Is there away to join/overlap two geotiff files (into one) and make the black color as transparent so missing areas are filled from the other file?