Cleo Drakos <cleo21drakos <at> gmail.com> writes: > > Thanks for your response.I tried the followings: > > > gcalc = 'C:\\Users\\cleo\\Documents\\gdalpys\\gdal_calc.py' > ##I produced second file (b)as the copy of first(a) > > a = 'D:\\a.tif' > b = 'D:\\b.tif' > outfile = 'D:\\result.tif' > expr = '(A-B)/(A+B)' > subprocess.call([sys.executable,gcalc,'-A',a,'--A_band','1','-B',b, '--B_band','0','--outfile',outfile,\ > > '--calc',expr,'--type','Float32','--format','ENVI'],shell=True) > a,b,outfile = None, None,None > > > Unfortunately, resulted file is completely black. > > > I hope someone can help me. Have you checked from the histogram that the result is totally black? I could imagine that bands 1 (A) and 2 (B) can have values close to each other which makes that A-B is close to zero. That divided by A+B makes the values even closer to zero and if such Float32 type image is opened in an image viewer without LUT stretch that could well appear as totally black. Forget all this if you have checked the histograms.
-Jukka Rahkonen- _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
