id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,cpu,platform 2048,i.pansharpen limited to 8-bit imagery,Nikos Alexandris,grass-dev@…,"Getting 11-bit IKONOS bands pan-sharpened by using i.pansharpen works only if the bands are rescaled to 8-bit, i.e. to range inside [0, 255]. In this case, color re-balancing (i.e. of Blue, Green and Red fusion-ed with Pan -IKONOS spectral bands) after the sharpening appears acceptable. Any other attempts using out of [0, 255] range values, for example using Top-of-Atmosphere Reflectances (floating point values < 1.0) or the raw IKONOS bands that range between [0, 2047], are not successful. Rescaling, however, might lead to some loss of spectral information (?). Hence, it may not be desired as pan-sharpening should not be limited in creating nice looking (pseudo-)color composites for viewing tasks (i.e. image interpretation) or printing. Sharpened/Fusioned images might as well be used as an input for segmentation/classification etc. Looking at the i.pansharpen source code ([http://lists.osgeo.org/pipermail/grass-user/2013-July/068700.html as suggested by Moritz Lennert in the grass-user mailing list]) ''I see that in all algorithms a function for histogram matching is called and IIUC, in that function, values seem to be limited to [0,255]''. Related code(lines): [http://trac.osgeo.org/grass/browser/grass/trunk/scripts/i.pansharpen/i.pansharpen.py#L348 def matchhist] and [http://trac.osgeo.org/grass/browser/grass/trunk/scripts/i.pansharpen/i.pansharpen.py#L379 arrays[i] = np.zeros((256,),dtype=('i4,f4'))] Not sure if this is a defect or an enhancement request. Many of the High Resolution images are frequently delivered in >8-bit formats.",defect,new,normal,7.6.2,Imagery,svn-trunk,,"i.pansharpen, sharpening, fusion, brovey, ihs, pca, 8-bit",,All,Unspecified