[GRASS-dev] [GRASS GIS] #2649: r.to.vect diagonals defect fixed

GRASS GIS GRASS GIS developer
1

#2649: r.to.vect diagonals defect fixed
-----------------------+----------------------------------------------------
Reporter: byronbest | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.0.1
Component: Default | Version: unspecified
Keywords: | Platform: Unspecified
      Cpu: x86-64 |
-----------------------+----------------------------------------------------
fails to break lines when value changes along diagonals

patch for 7.0.0 attached

tested in 6.4.3 on Amazon

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649&gt;
GRASS GIS <http://grass.osgeo.org>

2

#2649: r.to.vect diagonals defect fixed
-----------------------+----------------------------------------------------
Reporter: byronbest | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.0.1
Component: Raster | Version: unspecified
Keywords: | Platform: All
      Cpu: x86-64 |
-----------------------+----------------------------------------------------
Changes (by byronbest):

  * platform: Unspecified => All
  * component: Default => Raster

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>

3

#2649: r.to.vect diagonals defect fixed
-----------------------+----------------------------------------------------
Reporter: byronbest | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.0.1
Component: Raster | Version: unspecified
Keywords: r.to.vect | Platform: All
      Cpu: x86-64 |
-----------------------+----------------------------------------------------
Changes (by neteler):

  * keywords: => r.to.vect

Comment:

Can you please post a test case/screenshot to better understand the
problem?

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649#comment:2&gt;
GRASS GIS <http://grass.osgeo.org>

4

#2649: r.to.vect diagonals defect fixed
-----------------------+----------------------------------------------------
Reporter: byronbest | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.0.1
Component: Raster | Version: unspecified
Keywords: r.to.vect | Platform: All
      Cpu: x86-64 |
-----------------------+----------------------------------------------------

Comment(by byronbest):

Consider the result of r.drain, which is an already-thinned line of pixel
centres, obviously in "runs" of x,y moving +/- 1 in x and/or y. We'd like
for the runs be "collapsed" into only the corners where the direction
changes. Further, we'd like that running the stream on another grid
respect that we also need the corners where the color or value on the
resulting line changes. The segments will be given the color of the pixel
under the second of every pair.
r.to.vect already handles these runs when they are straight in the x or y,
but not in diagonals where both x and y change.
The attached before/after screen shots show where this has become a
visible defect.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649#comment:3&gt;
GRASS GIS <http://grass.osgeo.org>

5

#2649: r.to.vect diagonals defect fixed
-----------------------+----------------------------------------------------
Reporter: byronbest | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.0.1
Component: Raster | Version: unspecified
Keywords: r.to.vect | Platform: All
      Cpu: x86-64 |
-----------------------+----------------------------------------------------

Comment(by neteler):

All the tiff attachments seem to be broken (I tried two browsers), please
use PNG format for screenshots.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649#comment:4&gt;
GRASS GIS <http://grass.osgeo.org>

6

#2649: r.to.vect diagonals defect fixed
------------------------+-------------------------
  Reporter: byronbest | Owner: grass-dev@…
      Type: defect | Status: new
  Priority: normal | Milestone: 7.0.1
Component: Raster | Version: unspecified
Resolution: | Keywords: r.to.vect
       CPU: x86-64 | Platform: All
------------------------+-------------------------

Comment (by mlennert):

Has anyone been able to take a closer look at this patch ?

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2649#comment:5&gt;
GRASS GIS <http://grass.osgeo.org>