[GRASS-dev] [GRASS GIS] #3210: r.texture: bug when non continuous series of values

[GRASS GIS]

#3210: r.texture: bug when non continuous series of values
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  Reporter:  mlennert     |      Owner:  grass-dev@…
      Type:  defect       |     Status:  reopened
  Priority:  normal       |  Milestone:  7.2.0
 Component:  Raster       |    Version:  svn-trunk
Resolution:               |   Keywords:  r.texture
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by mmetz):

 Replying to [comment:26 mlennert]:
 > Replying to [comment:25 mmetz]:
 > > [...] Could you update the manual if you can suggest applications for
 these texture measurments? Thanks!
 >
 > I just committed what I consider some improvements, including a very
 simple, but thus hopefully pedagogical, example. I allowed myself to
 rearrange some of the existing text, including some of your recent
 additions.

 Thanks for your update on the manual! I am trying to make r.texture
 produce correct results in a reasonable time, but you are actually using
 it, so you know best what should go into the manual. IMHO, the description
 of a manual should be as short as possible (what does the module do, what
 is its output good for). Technical details should go into Notes. In order
 to keep the description short, I suggest to move the second last paragraph
 of the description to notes.
 >
 > Please have a look and if you think this is ok, we can backport to the
 other branches.

 You decide.

 About the current defaults of r.texture:

 The default size of the moving window is 3, and I suspect that the reason
 for this small size is processing time, After what I read, common sizes
 are in the range of 20 - 50 (Haralick et al. (1973): 64), the reason is
 probably calculating texture measurements for a few sample regions. In a
 moving window approach as in r.texture, a smaller window size seems
 reasonable, but a size of 3 might be too small to capture texture in the
 current area.

 We could remove cropping at margins, the results would not be perfect, but
 better than nothing.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3210#comment:27>
GRASS GIS <https://grass.osgeo.org>