pnmdepth(1) [osf1 man page]

pnmdepth(1)						      General Commands Manual						       pnmdepth(1)

NAME

       pnmdepth - change the maxval in a portable anymap

SYNOPSIS

       pnmdepth newmaxval [pnmfile]

DESCRIPTION

       Reads a portable anymap as input.  Scales all the pixel values, and writes out the image with the new maxval.  Scaling the colors down to a
       smaller maxval will result in some loss of information.

       Be careful of off-by-one errors when choosing the new maxval.  For instance, if you want the color values to be five bits wide, use a  max-
       val of 31, not 32.

       One  important  use  of pnmdepth is to convert a new format 2-byte-per-sample PNM file to the older 1-byte-per-sample format.  Before April
       2000, essentially all raw (binary) format PNM files had a maxval less than 256 and one byte per sample, and many programs may rely on that.
       If  you	specify  a  newmaxval  less than 256, the resulting file should be readable by any program that worked with PNM files before April
       2000.

SEE ALSO

       pnm(5), ppmquant(1), ppmdither(1)

AUTHOR

       Copyright (C) 1989, 1991 by Jef Poskanzer.

								   08 April 2000						       pnmdepth(1)

Check Out this Related Man Page

pgmedge(1)                                                    General Commands Manual                                                   pgmedge(1)

NAME

       pgmedge - edge-detect a portable graymap

SYNOPSIS

       pgmedge [pgmfile]

DESCRIPTION

       Reads  a  portable  graymap  as  input.   Outlines  the edges, and writes a portable graymap as output.  Piping the result through pgmtopbm
       -threshold and playing with the threshold value will give a bitmap of the edges.

       The edge detection technique used is to take the Pythagorean sum of two Sobel gradient operators at 90 degrees to  each  other.   For  more
       details see "Digital Image Processing" by Gonzalez and Wintz, chapter 7.

       The  maxval  of the output is the same as the maxval of the input The effect is better with larger maxvals, so you may want to increase the
       maxval of the input by running it through pnmdepth first.

SEE ALSO

       pgmenhance(1), pgmtopbm(1), pnmdepth(1), pgm(5), pbm(5)

AUTHOR

       Copyright (C) 1991 by Jef Poskanzer.

                                                                 04 February 1990                                                       pgmedge(1)

Linux and UNIX Man Pages

pnmdepth(1) [osf1 man page]

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