pgmcompare(1)

NAME

pgmcompare - compare two greyscale images

SYNOPSIS

pgmcompare [-s] <file1> <file2> [<percent> [<type>]]

DESCRIPTION

pgmcompare compares two greyscale images file1 and file2 and prints out statistics. The mean square error (MSE), root mean square error (RMSE) and peak signal noise ratio (PSNR) are useful for comparing two supposedly identical images, while the L^q and L^q_d norms can be used to compare the similarity of two possibly different images. In any case, the lower the value, the more similar the images are.

The percentage of the coefficients in the Wavelet domain to be compared for the L^q and L^q_d measures can be specified as the percent argument. Also the L^q and L^q_d measures can be optimized for drawn (0) or scanned (1) images using the type argument.

Since the L^q and L^q_d computation is time consuming it can be switched off if not needed by specifying the -s option.

NOTES

The pgmcompare 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, pgmcompare may, if enabled, also be able to read PFI files. However using different file formats in the same command line may not be a good idea.

BUGS

None known yet.

COPYRIGHT
Copyright (C) 2001-2003 Herbert

pgmcompare 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.

pgmcompare 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>