Manual: pamedge

Pamedge User Manual(1)				   General Commands Manual			      Pamedge User Manual(1)

NAME
       pamedge - edge-detect an image

SYNOPSIS
       pamedge [imagefile]

DESCRIPTION
       This program is part of Netpbm(1).

       pamedge reads a Netpbm image (PNM or PAM) and produces an image that outlines the edges.

       The  output  image  is of the same type as the input, except that the maxval of the output is at least 255 and if the
       input is PBM, the output is PGM.

       You can pipe the result through pamditherbw -threshold and play with the threshold value to get a PBM (bilevel image)
       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, except at least 255.  The effect is better with
       larger maxvals, so you may want to increase the maxval of the input by running it through pamdepth first.

OPTIONS
       There are no command line options defined specifically for pamedge, but it recognizes the options common to all	pro‐
       grams based on libnetpbm (See  Common Options .)

SEE ALSO
       pgmenhance(1), pamditherbw(1), pamdepth(1), pammasksharpen(1), pamsharpness(1), pamsharpmap(1), pam(1), pnm(1)

HISTORY
       pamedge was added to Netpbm in Release 10.14 (March 2003).  It replaced pgmedge, which was the same thing, but worked
       only on PGM and PBM images.

AUTHOR
       Copyright (C) 1991 by Jef Poskanzer.  Adapted to pnmedge Peter Kichgessner in 1995, and then to pamedge by Bryan Hen‐
       derson in 2003.

DOCUMENT SOURCE
       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation is at

	      http://netpbm.sourceforge.net/doc/pamedge.html

netpbm documentation				       11 January 2003				      Pamedge User Manual(1)