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- pgmnorm(1) PBM Plus pgmnorm(1)
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- NAME
- pgmnorm - normalize the contrast in a portable graymap
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- SYNOPSIS
- pgmnorm [-bpercent <n> | -bvalue <n>] [-wpercent <n> |
- -wvalue] [pgmfile]
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- DESCRIPTION
- Reads a portable graymap as input. Normalizes the contrast
- by forcing the lightest pixels to white, the darkest pixels
- to black, and linearly rescaling the ones in between; and
- produces a portable graymap as output.
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- By default, the darkest 2 percent of all pixels are mapped
- to black, and the lightest 1 percent are mapped to white.
- You can override these percentages by using the -bpercent
- and -wpercent flags, or you can specify the exact pixel
- values to be mapped by using the -bvalue and -wvalue flags.
- Appropriate numbers for the flags can be gotten from the
- pgmhist tool.
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- All flags can be abbreviated to their shortest unique pre-
- fix.
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- SEE ALSO
- pgmhist(1), pgm(5)
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- AUTHOR
- Partially based on the fbnorm filter in Michael Mauldin's
- "Fuzzy Pixmap" package.
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- Copyright (C) 1989 by Jef Poskanzer.
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- Permission to use, copy, modify, and distribute this
- software and its documentation for any purpose and without
- fee is hereby granted, provided that the above copyright
- notice appear in all copies and that both that copyright
- notice and this permission notice appear in supporting docu-
- mentation. This software is provided "as is" without
- express or implied warranty.
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- Printed 5/25/90 28 February 1989 1
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