1r.bitpattern(1)               Grass User's Manual              r.bitpattern(1)
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NAME

6       r.bitpattern  - Compares bit patterns with a raster map
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KEYWORDS

9       raster
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SYNOPSIS

12       r.bitpattern
13       r.bitpattern help
14       r.bitpattern [-q] input=name output=name pattern=integer patval=integer
15       [--overwrite]
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17   Flags:
18       -q  Quiet
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20       --overwrite
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22   Parameters:
23       input=name
24           Name of input raster map
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26       output=name
27           Name for output raster map
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29       pattern=integer
30           Bit pattern position(s)
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32       patval=integer
33           Bit pattern value
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DESCRIPTION

36       r.bitpattern performs bit pattern comparisons.  The module can be  used
37       to pixelwise verify a satellite image for low quality pixels if a Qual‐
38       ity Control Bit Index map is provided (e.g. as for MODIS sensor  maps).
39       The functionality is two-fold:
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41       1      define position: set bit(s) to 1 which shall match, then convert
42              this position pattern to integer, set  pattern=  parameter  with
43              that integer value
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45       2      define  pattern  *value* which should be in that position: first
46              bit pattern of value, convert to integer, set patval= parameter
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48       If several bitpatterns have to be tested, the  resulting  maps  can  be
49       used  to  exclude  low quality pixel in the input satellite image using
50       r.mapcalc (OR and NOT operators).
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EXAMPLE

53       1      define position:
54                   xx xx 1x xx
55                   binary: 1000 -> integer: 8 -> pattern=8
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58       2      define value:
59                      Ex.: we want to check for 0 in that position
60                   xx xx 0x xx
61                   binary: 0000 -> integer: 0 -> patval=0
62                      if value can be arbitray (0/1), then assume 0 value
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SEE ALSO

66        r.mapcalc
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AUTHORS

69       Radim Blazek, Markus Neteler
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71       Last changed: $Date: 2005/08/10 09:15:03 $
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73       Full index
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77GRASS 6.2.2                                                    r.bitpattern(1)