This is just intriguing while not blocking my way, but I wonder what is going on and would like to get feedbacks from more experienced users.
1) Given a trans.png file (1.1MB) looks good and conserve transparencies (Stackexchanges displays below an altered version as .jpg) :
2) I restore georeferencing using :
gdal_translate -a_ullr 67.0 37.5 99.0 27.0 -co COMPRESS=LZW -co ALPHA=YES ./trans.png ./trans.gis.tif
3) The output trans.gis.tif (1.6MB) looks good and conserve transparencies (Stackexchanges displays below an altered version as .jpg):
4) Loading it in Quantum GIS, it get well positionned (georeferencing works!), but the image is ill colored with the darkest areas (and only them!) becoming green :
Is this green artifact normal ? How to fix it (so I may see the expected black pixels) ?
Edit: file added in 1)