.TL Pnminvert User Manual .SH 1 pnminvert .LP Updated: 08 August 1989 .br Table Of Contents .SH 2 NAME .LP pnminvert - invert a PNM image .SH 2 SYNOPSIS .LP \fBpnminvert\fR [\fIpnmfile\fR] .SH 2 DESCRIPTION .LP .LP This program is part of Netpbm. .LP \fBpnminvert\fR reads a PNM image as input, inverts it black for white, and produces a PNM image as output. .LP If the image is grayscale, \fBpnminvert\fR replaces a pixel with one of complementary brightness, i.e. if the original pixel has gamma-adjusted gray value G, the output pixel has gray value maxval - G. .LP If the image is color, \fBpnminvert\fR inverts each individual RGB component the same as for a grayscale image. .SH 2 SEE ALSO .LP pnm .SH 2 AUTHOR .LP Copyright (C) 1989 by Jef Poskanzer. .br \l'5i' .SH 2 Table Of Contents .LP .IP \(bu NAME .IP \(bu SYNOPSIS .IP \(bu DESCRIPTION .IP \(bu SEE ALSO .IP \(bu AUTHOR .LP