Files are from: https://maps.lib.utexas.edu/maps/topo/vietnam/
My PDF reader can read the image but when importing it into QGIS it gives me a cyan rectangle inside a black one which I suspect is the
NEATLINE bounding box.
I tried using gdal_translate to convert them in GeoTIFF
gdal_translate ban_buc-5951-4.pdf test.tif -of GTiff
resulting in no error being thrown but
test.tif is of the right dimension but all white
gdalinfo -mdd LAYERS ban_buc-5951-4.pdf
don't show any layer names
I saw a
GDAL_USER_PWD, would that mean that those file could be password protected?