.\"
.\" wm_corvi_e.1 - the *roff document processor man page source
.\"
.TH wm_corvi_e 1 "98/07/29" "Watermarking, Version 1.0"
.SH NAME
.B wm_corvi_e
\- a program to embed a signature in the DWT residue of an image
.SH SYNOPSIS
.B wm_corvi_e
[
.BI \-a \ number
]
[
.BI \-e \ number
]
[
.BI \-f \ number
]
[
.BI \-F \ ffile
]
[
.BI \-g \ number
]
[
.B \-h
]
[
.BI \-o \ ofile
]
.br
[
.BI \-q \ number
]
[
.BI \-v \ number
]
.BI \-s \ sfile
.I file
.SH DESCRIPTION
.B wm_corvi_e
is a program to embed a signature (watermark) from
.I sfile
into the DWT residue of an image
.I file
and output a signed (watermarked) image
.I ofile.
Both, input and output image,
are in PGM (portable graymap) format.
.PP
If
.I file
or
.I ofile
is not specified, then standard input or standard output is
used. The signature
.I sfile
is a mandatory parameter however.
.PP
.B gen_corvi_sig
is used to generate a signature file,
.B wm_corvi_d
extracts a signature from a watermarked image and
.B cmp_corvi_sig
allows to compare and test an extracted watermark against the original
signature.
.PP
Please refer to Marco Corvi's paper "Wavelet-based image watermarking
for copyright protection", to get an idea about the algorithm.
.PP
.SH OPTIONS
.TP
.BI \-a \ number
Alpha factor that determines embedding strength of the signature.
Allows to override the setting in the signature file.
.TP
.BI \-e \ number
Wavelet filtering method for forward transformation. 
Allows to override the setting in the signature file.
.TP
.BI \-f \ number
Wavelet filter number. 
Allows to override the setting in the signature file.
.TP
.BI \-F \ ffile
Wavelet filter definition file.
Allows to override the setting in the signature file.
.TP
.BI \-g \ number
Wavelet filtering method for inverse transformation. 
Allows to override the setting in the signature file.
.TP
.B \-h
Print a help message.
.TP
.BI \-o \ ofile
Output watermarked image to the specified
.I file
instead of standard output.
.TP
.BI \-q \ number
Set quantization/quality factor. Overrides the setting in the signature
file.
.TP
.BI \-s \ sfile
The signature file to embed into the input image. See
.B gen_corvi_sig
(1) for a description of the file format. Mandatory parameter.
.IR file
Input image in PGM format to sign (watermark). Default: standard input.
.TP
.BI \-v \ number
Verbosity level. Specify higher numbers for more informatative
output. Default value: 0.
.TP
.I file
The image in PGM format to be watermarked.
.PP
.SH OUTPUT
The signed (watermarked) image in PGM format is written to standard output
or, optionally, to
.I ofile.
The length of the signature (watermark) determines the level of the 
image residue (coarse image) where the signature is embedded.
.PP
.SH AUTHOR
Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at.
.SH AVAILABILITY
The most recent released version of
.B wm_corvi_e
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 gen_corvi_sig
(1),
.BR wm_corvi_d
(1),
.BR wm_corvi_s
(1),
.BR cmp_corvi_sig
(1)