From 950f819f0c2660f286ab44e31650a88a9159b090 Mon Sep 17 00:00:00 2001 From: giraffedata Date: Sun, 22 Mar 2015 22:42:57 +0000 Subject: miscellaneous update git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@2417 9d0c8265-081b-0410-96cb-a4ca84ce46f8 --- pnmhisteq.html | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) (limited to 'pnmhisteq.html') diff --git a/pnmhisteq.html b/pnmhisteq.html index d73857c6..2e7ccfd0 100644 --- a/pnmhisteq.html +++ b/pnmhisteq.html @@ -2,7 +2,7 @@ Pnmhisteq User Manual

pnmhisteq

-Updated: 02 February 2010 +Updated: 22 March 2015
Table Of Contents @@ -16,6 +16,9 @@ pnmhisteq - histogram equalize a PNM image [-gray] +[-noblack] +[-nowhite] + [-rmap pgmfile] [-wmap pgmfile] @@ -111,6 +114,27 @@ annotations you don't want modified. Weather satellite images that show continent outlines in color are best processed using this option. The option has no effect when the input is a graymap. +

-noblack + +

Do not include black pixels in the equalization. The black pixels in the +output are exactly the black pixels in the input and the number of black +pixels does not affect the color of any other pixels. + +

Sometimes, black isn't as much a color as a background or annotation for +the real colors, so you want to treat it specially this way. Think of a +picture of stars, which is nearly all black, but with lots of stars of +different brightness. You want to change the brightnesses of the stars to +maximize contrast between them, but if you considered the blackness to be +significant, all the stars would end up close to full white. + +

This option was new in Netpbm 10.70 (March 2015). + +

-nowhite + +

Same as -noblack, but for the white pixels. + +

This option was new in Netpbm 10.70 (March 2015). +

-rmap mapfile

Process the image using the luminosity map specified by the PGM -- cgit 1.4.1