Man page or keyword search:   man All Sections 1 - General Commands 2 - System Calls 3 - Subroutines, Functions 4 - Special Files 5 - File Formats 6 - Games and Screensavers 7 - Macros and Conventions 8 - Maintenence Commands 9 - Kernel Interface New Commands Server 4.4BSD AIX Alpinelinux Archlinux Aros BSDOS BSDi Bifrost CentOS Cygwin Darwin Debian DigitalUNIX DragonFly ElementaryOS Fedora FreeBSD Gentoo GhostBSD HP-UX Haiku Hurd IRIX Inferno JazzOS Kali Knoppix LinuxMint MacOSX Mageia Mandriva Manjaro Minix MirBSD NeXTSTEP NetBSD OPENSTEP OSF1 OpenBSD OpenDarwin OpenIndiana OpenMandriva OpenServer OpenSuSE OpenVMS Oracle PC-BSD Peanut Pidora Plan9 QNX Raspbian RedHat Scientific Slackware SmartOS Solaris SuSE SunOS Syllable Tru64 UNIXv7 Ubuntu Ultrix UnixWare Xenix YellowDog aLinux   17783 pages apropos Keyword Search (all sections) Output format html ascii pdf view pdf save postscript

Pamedge User Manual(0)					Pamedge User Manual(0)

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 max‐
       val  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.

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 Henderson in 2003.

netpbm documentation		11 January 2003		Pamedge User Manual(0)

Vote for polarhome