cmp_dct(1)

NAME
cmp_dct - a program to create the difference image of the frequency domain of two PGM images

SYNOPSIS
cmp_dct [ -h ] [ -m number ] [ -o ofile ] -i ifile file

DESCRIPTION
cmp_dct is a program to create the difference image of the frequency domain of two PGM (portable graymap) grayscale images. To compare images in the spatial domain, either in PPM (portable pixmap) format for RGB color images or in PGM (portable graymap) format for grayscale images, use the cmp_ppm program or the cmp_pgm program, respectively.

If file or ofile is not specified, then standard input or standard output is used.

OPTIONS

-h  Print a help message.

-i ifile
    The original image. Mandatory.

-m number
    Multiplication factor to magnify differences between the to original and input image. Default value: 16.

-o ofile
    Output image file to contain the difference image in PGM format.

file
    Input image that is compared against ifile. Default: standard input.

OUTPUT
The difference image in PGM format is written to standard output or, optionally, to ofile.

AUTHOR
Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at.

AVAILABILITY
The most recent released version of cmp_dct is always available at http://www.cosy.sbg.ac.at/~pmeerw/Watermarking or via anonymous ftp from ftp.cosy.sbg.ac.at in the directory /pub/people/pmeerw/Watermarking.

SEE ALSO
cmp_pgm (1), cmp_ppm (1), cmp_dct8x8 (1)