.\"
.\" gen_corvi_sig.1 - the *roff document processor man page source
.\"
.TH gen_corvi_sig 1 "98/07/17" "Watermarking, Version 1.0"
.SH NAME
.B gen_corvi_sig
\- a program to generate a signature for
the
.B wm_corvi_e
watermarking program
.SH SYNOPSIS
.B gen_corvi_sig
[
.BI \-a \ number
]
[
.BI \-d \ number
]
[
.BI \-e \ number
]
[
.BI \-f \ number
]
[
.BI \-F \ ffile
]
[
.BI \-g \ number
]
.br
[
.B \-h
]
[
.BI \-m \ number
]
[
.BI \-n \ number
]
[
.BI \-o \ file
]
[
.BI \-q \ number
]
[
.BI \-s \ number
]
.SH DESCRIPTION
.B gen_corvi_sig
is a program to generate a signature to be
embedded with the
.B wm_corvi_e
watermarking program and extracted with the
.B wm_corvi_d
program. The
.B cmp_corvi_sig
program is used to compare and test an
extracted signature with the original signature.
.PP
Please refer to Marco Corvi's paper "Wavlet-based image watermarking
for copyright protection", to get an idea of the algorithm.
.PP
.SH OPTIONS
.TP
.BI \-a \ number
Alpha factor that determines embedding strength of the signature. Default
value 0.3.
.TP
.BI \-d \ number
Deviation for the normal distributed signature values, default 1.0.
.TP
.BI \-e \ number
The filtering method for the forward wavelet transform. Default value
1.
.TP
.BI \-F \ ffile
The filter definition file. Default
.I filter.dat.
.TP
.BI \-f \ number
Use the
.I number
filter from the filter definition file,
.I ffile. Default: 1.
.TP
.BI \-g \ number
The filtering method for the inverse wavelet transform. Default value
2.
.TP
.B \-h
Print a help message.
.TP
.BI \-m \ number
Mean of the normal distributed signature values, default 0.0.
.TP
.BI \-n \ number
Length of the watermark. Default value 100.
.TP
.BI \-o \ file
Output signature to the specified
.I file
instead of standard output.
.TP
.BI \-q \ number
Quantization/quality factor. Default value 3.
.TP
.BI \-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.
.PP
.SH OUTPUT
The output file has the following format:
.TP
.B CVSG
Magic to identify file type.
.TP
.I number
The length of the signature in bits.
.TP
.I number
The alpha factor (embedding strength).
.TP
.I number
The quantization/quality factor.
.TP
.I number
The wavelet forward transform filtering method.
.TP
.I number
The wavelet filter number.
.TP
.I file
The wavelet filter definition file name.
.TP 
.I number
The wavelet inverse transform filtering method.
.TP
.I numbers
The actual normal distributed signature values, one per line.
.PP
.SH AUTHOR
Peter Meerwald.
Email bug reports to pmeerw@cosy.sbg.ac.at.
.SH AVAILABILITY
The most recent released version of
.B gen_corvi_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.
.SH "SEE ALSO"
.BR wm_corvi_e
(1),
.BR wm_corvi_d
(1),
.BR wm_corvi_s
(1),
.BR cmp_corvi_sig
(1)