Image processing

Ideas collection for improving GRASS' Image processing capabilities

Below modules need some tuning before being added to GRASS 6. Volunteers welcome.

Spectral unmixing

• i.spec.unmix (source code)

Spectral angle mapping

• i.spec.sam (source code)

Geocoding

• i.points.auto: automated search of GCPs based on FFT correlation (as improved i.points)
• i.homography: geocoding with lines (instead of points) with homography (as improved i.points)
• support splines from GDAL (see GRASS_AddOns#Imagery_add-ons)

Image classification

• pr: C code for classification problems
• GRASS implementation: i.pr.* source code is available here)

Improving the existing code

It might be sensible to merge the various image libraries:

• GRASS 6 standard libs:
  • lib/imagery/: standard lib, in use (i.* except for i.points3, i.rectify3)
  • imagery/i.ortho.photo/libes/: standard lib, in use (i.ortho.photo, photo.*)
• GRASS 5 (! only) image3 lib:
  • lib/image3/: never finished improvement which integrated the standard lib and the ortho lib. Seems to provide also ortho rectification for satellite data (i.points3, i.rectify3)
• GRASS 5/6 image proc commands:
  • merge of i.points, i.vpoints, i.points3
  • merge of i.rectify and i.rectify3
  • addition of new resampling algorithms such as bilinear, cubic convolution (take from r.proj or upcoming r.resamp.aggreg)
  • add other warping methods (maybe thin splines from GDAL?)
  • implement/finish linewise ortho-rectification of satellite data