[GRASS-dev] [GRASS GIS] #2048: i.pansharpen limited to 8-bit imagery

[GRASS GIS]

#2048: i.pansharpen limited to 8-bit imagery
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 Reporter:  nikosa                                                     |       Owner:  grass-dev@…              
     Type:  defect                                                     |      Status:  new                      
 Priority:  normal                                                     |   Milestone:  7.0.0                    
Component:  Imagery                                                    |     Version:  svn-trunk                
 Keywords:  i.pansharpen, sharpening, fusion, brovey, ihs, pca, 8-bit  |    Platform:  Unspecified              
      Cpu:  All                                                        |  
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Comment(by cmbarton):

 For pan sharpening, the reason for histogram matching is that the higher
 resolution pan image needs to replace one of the lower resolution images
 as part of the sharpening algorithm. So the pan band needs to be histogram
 matched to the one it is replacing. This is why I don't think that
 matching it to an average of all bands is a good idea. I could be
 mistaken, but it seems incorrect conceptually.

 The routine I used is the standard one discussed for this. There may well
 be a more accurate one and a better way to deal with floating point and
 large integer data. Using numpy arrays makes this one quite fast. It might
 benefit from parallelization in some way. I parallelized other parts of
 the code but not this one. So, yes, if there is a student out there with
 not enough to do...   ;-)

 Michael

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2048#comment:9>
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