gen_cox_sig(1)

NAME
gen_cox_sig - a program to generate a signature for the wm_cox_e watermarking program

SYNOPSIS
gen_cox_sig [ -a number ] [ -d number ] [ -h ] [ -m number ] [ -n number ] [ -o file ] [ -q number ] [ -s number ]

DESCRIPTION
gen_cox_sig is a program to generate a signature to be embedded with the wm_cox_e watermarking program and extracted with the wm_cox_d program. The cmp_cox_sig program is used to compare and test an extracted signature with the original signature.

Please refer to Ingemar J. Cox's paper "Secure Spread Spectrum Watermarking for Multimedia", 1995, to get an idea about the algorithm.

OPTIONS

-a number
    Alpha factor that determines embedding strength of the signature. Default value 0.3.

-d number
    Deviation for the normal distributed signature values, default 1.0.

-h  Print a help message.

-m number
    Mean of the normal distributed signature values, default 0.0.

-n number
    Length of the watermark. Default value 100.

-o file
    Output signature to the specified file instead of standard output.

-q number
    Quantization/quality factor. Default value 3.

-s number
    Specify a seed value to initialize the pseudo-random number generator; if not specified, time and pid (process id) are used to initialize the pseudo-random number generator.

OUTPUT
The output file has the following format:

CXSG
    Magic to identify file type.

number
    The length of the signature in bits.

number
    The alpha factor (embedding strength).

number
    The quantization/quality factor.

numbers
    The actual normal distributed signature values, one per line.

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

AVAILABILITY
The most recent released version of gen_cox_sig 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
wm_cox_e (1), wm_cox_d (1), cmp_cox_sig (1)