[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 nikosa):

 Replying to [comment:4 cmbarton]:
 > If you have an image set that is more than 8bit, I can use it to test
 some things.

 Unfortunately I cannot share the data I work with.  However, there are
 publicly available 11-bit IKONOS images:
 [ftp://ftp.glcf.umd.edu/glcf/China_earthquake_May_2008/IKONOS/]


 > i.histo.match is a nice module. But its objective is different from
 histogram matching in i.pan.sharpen.

 Unfortunately i.histo.match has its own limitation(s): it understands only
 integers - no floating points. See [http://lists.osgeo.org/pipermail
 /grass-dev/2013-February/062161.html].  Though, not limited to 2^8^.


 > So it would need modification to be used in this context. When I was
 writing i.pan.sharpen, I looked at the i.histo.match code but it was
 easier to use a much simpler algorithm. But since you know i.histo.match
 maybe you can see where the code could be modified to be used in
 i.pan.sharpen.

 Maybe... It certainly would be a nice quick-"fix" if i.pansharpen can be
 released from being restricted to 2^8^? I mean, to expand in the "integer"
 planet as a first step?

 Will try to check further in the coming days/week.  However, I'd like to
 kindly ask again if it is possible to alter the documentation?  It is not
 a nice surprise trying to work with i.pansharpen and getting strange
 colors or empty images as a result.  See also
 [http://gis.stackexchange.com/q/39174/5256].  At least mention the current
 limitation or... other ideas?  Then again, it is in G7, the development
 version :-)

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2048#comment:5>
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