pgmscale(1)

NAME

pgmscale - scales a greyscale image

SYNOPSIS

pgmscale <infile> <outfile> <factor> [<function> [<stages> [<filter> [hlfunc [lhfunc]]]]]

DESCRIPTION

pgmscale opens infile, scales it by factor, and writes it to outfile. For the scalement different approximation functions can be used. If function is 0 (default), bilinear interpolation is used. Other valid values: 1: dumb average, 2 nearest neighbour, 3: horizontal linear interpolation, 4: vertical linear interpolation.

If stages is greater than 0, the image will be decomposed by that number of stages before the scalement is performed. In that case the scaled image will be reconstructed by the same number of stages before saving. The filter can be specified, too. The decomposition feature is experimental and will normally not result in usable images. Ignore this feature and use function number 0 to get good results. The functions used on the HL and LH detail areas can be set separately by hlfunc (for HL) and lhfunc (for LH). Again this is a purely experimental feature.

NOTES

The pgmscale utility is part of the Wavelet class library package. The version number refers to the whole package rather than to the utility.

Apart from PGM, pgmscale may, if enabled, also be able to read PFI files.

BUGS

None known yet.

COPYRIGHT
Copyright (C) 2001-2003 Herbert

pgmscale is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

pgmscale is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

AUTHOR
Herbert Martin Dietze <herbert@spamcop.net>