pgmslice(1) [freebsd man page]

pgmslice(1)                                                   General Commands Manual                                                  pgmslice(1)

NAME

       pgmslice - extract one line of pixel values out of a portable graymap

SYNOPSIS

       pgmslice -row|-col line [pgmfile]

DESCRIPTION

       Extracts  one  line  of  pixel values out of a portable graymap and outputs it in a two column ascii format, with the first value being the
       pixel's position in the line and the second value the pixel's greyscale value. This is useful for making cross sections through, for  exam-
       ple, greyscale CCD images.

OPTIONS

       -row   Extract a row of pixels

       -col   Extract a column of pixels

SEE ALSO

       pgm(5)

AUTHOR

       pgmslice  was  written by Jos Dingjan <jos@tuatha.org> after being unable to find the source code to Marco Beijersbergen's program with the
       same name.

                                                                    22 May 2000                                                        pgmslice(1)

pgmnorm(1)						      General Commands Manual							pgmnorm(1)

NAME

       pgmnorm - normalize the contrast in a portable graymap

SYNOPSIS

       pgmnorm [-bpercent N | -bvalue N] [-wpercent N | -wvalue N] [pgmfile]

DESCRIPTION

       Reads  a portable graymap as input.  Normalizes the contrast by forcing the lightest pixels to white, the darkest pixels to black, and lin-
       early rescaling the ones in between; and produces a portable graymap as output.

OPTIONS

       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.  If you just want to enhance the contrast,  then
       choose  values  at  elbows in the histogram; e.g. if value 29 represents 3% of the image but value 30 represents 20%, choose 30 for bvalue.
       If you want to lighten the image, then set bvalue to 0 and just fiddle with wvalue; similarly, to darken the image, set	wvalue	to  maxval
       and play with bvalue.

       All flags can be abbreviated to their shortest unique prefix.

SEE ALSO

       pgmhist(1), ppmnorm(1), pgm(5)

AUTHOR

       Partially based on the fbnorm filter in Michael Mauldin's "Fuzzy Pixmap" package.

       Copyright (C) 1989 by Jef Poskanzer.

								 28 February 1989							pgmnorm(1)