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]  [--verbose]  [--quiet]
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17   Flags:
18       -q
19           Quiet
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21       --overwrite
22           Allow output files to overwrite existing files
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24       --verbose
25           Verbose module output
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27       --quiet
28           Quiet module output
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30   Parameters:
31       input=name
32           Name of input raster map
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34       output=name
35           Name for output raster map
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37       pattern=integer
38           Bit pattern position(s)
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40       patval=integer
41           Bit pattern value
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DESCRIPTION

44       r.bitpattern performs bit pattern comparisons.  The module can be  used
45       to pixelwise verify a satellite image for low quality pixels if a Qual‐
46       ity Control Bit Index map is provided (e.g. as for MODIS sensor  maps).
47       The functionality is two-fold:
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49       1      define position: set bit(s) to 1 which shall match, then convert
50              this position pattern to integer, set  pattern=  parameter  with
51              that integer value
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53       2      define  pattern  *value* which should be in that position: first
54              bit pattern of value, convert to integer, set patval= parameter
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56       If several bitpatterns have to be tested, the  resulting  maps  can  be
57       used  to  exclude  low quality pixel in the input satellite image using
58       r.mapcalc (OR and NOT operators).
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EXAMPLE

61       1      define position:
62                   xx xx 1x xx
63                   binary: 1000 -> integer: 8 -> pattern=8
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66       2      define value:
67                      Ex.: we want to check for 0 in that position
68                   xx xx 0x xx
69                   binary: 0000 -> integer: 0 -> patval=0
70                      if value can be arbitray (0/1), then assume 0 value
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SEE ALSO

74        r.mapcalc
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AUTHORS

77       Radim Blazek, Markus Neteler
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79       Last changed: $Date: 2005-08-10 11:15:03 +0200 (Wed, 10 Aug 2005) $
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81       Full index
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83       © 2003-2008 GRASS Development Team
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87GRASS 6.3.0                                                    r.bitpattern(1)