NAME

pnminvert - invert a PNM image

SYNOPSIS

pnminvert

[pnmfile]

DESCRIPTION

This program is part of Netpbm(1)

pnminvert reads a PNM image as input, inverts it black for white, and produces a PNM image as output.

If the image is grayscale, pnminvert 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.

If the image is color, pnminvert inverts each individual RGB component the same as for a grayscale image.

SEE ALSO

pnm(5)

AUTHOR

Copyright (C) 1989 by Jef Poskanzer.