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

[GRASS GIS]

#2048: i.pansharpen limited to 8-bit imagery
-----------------------------------------------------------------------+----
 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                                                        |  
-----------------------------------------------------------------------+----

Comment(by cmbarton):

 Replying to [comment:15 nikosa]:
 > Replying to [comment:14 cmbarton]:
 > > Does someone have a small sample set of images to test in order to
 work out alternatives to 8bit image matching?
 >
 >
 > See, for example, publicly available IKONOS images:
 [ftp://ftp.glcf.umd.edu/glcf/China_earthquake_May_2008/IKONOS/].  I did
 all the series of tests (as postes in the mailing list) with the first one
 [ftp://ftp.glcf.umd.edu/glcf/China_earthquake_May_2008/IKONOS/po_58204_0000000.20001116
 .China-Sichuan/]
 >
 > I also have a small script to pan-sharpen DNs, Radiance and Reflectancs
 (given all of the pre-processing has been done and some naming conventions
 are followed):
 >
 >
 > {{{
 > for Method_Input in "ihs DNs" "ihs Radiance" "ihs ToAR" \
 > "brovey DNs" "brovey Radiance" "brovey ToAR" \
 > "pca DNs" "pca Radiance" "pca ToAR"
 >
 > do
 >
 >   # parse "${Method_STR}" and set positional parameters
 >   set -- $Method_Input ; echo $1 $2
 >
 >   # some echo
 >   echo "Pan-Sharpening the <${2}> images based on the <${1}> method"
 >
 >   i.pansharpen \
 >   sharpen=${1} \
 >   pan=Pan_${2} \
 >   ms1=Blue_${2} \
 >   ms2=Green_${2} \
 >   ms3=Red_${2} \
 >   output=sharp_${1}_${2}
 >
 > done
 > }}}
 >
 >
 >
 > > A key issue is that it will be necessary to know the potential value
 range for the images.
 >
 > If it's an 11-bit image, the the input can be fixed to [0,2047]?
 Actually, most of the data come in either 8-bit or 16-bit form.  The
 latter for not loosing the fine detail of >8-bit sensors (me thinks).
 >
 >
 > > I don't see a way around this being a user-entered value. Maybe there
 also needs to be a flag for floating point.
 >
 > Can't this be automated in Python?  Right, RTFM for myself :D

 Actually, Python doesn't care if it is floating point or not (although you
 can specify). It's the GRASS routines that matter most, especially r.stats
 and r.mapcalc (can't can't change this for r.his.rgb/r.rgb.his or i.pca).

 Michael

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/2048#comment:16>
GRASS GIS <http://grass.osgeo.org>