wm_corvi_e(1)

NAME
wm_corvi_e - a program to embed a signature in the DWT residue of an image

SYNOPSIS
wm_corvi_e [ -a number ] [ -e number ] [ -f number ] [ -F ffile ] [ -g number ] [ -h ] [ -o ofile ]
[ -q number ] [ -v number ] -s sfile file

DESCRIPTION
wm_corvi_e is a program to embed a signature (watermark) from sfile into the DWT residue of an image file and output a signed (watermarked) image ofile. Both, input and output image, are in PGM (portable graymap) format.

If file or ofile is not specified, then standard input or standard output is used. The signature sfile is a mandatory parameter however.

gen_corvi_sig is used to generate a signature file, wm_corvi_d extracts a signature from a watermarked image and cmp_corvi_sig allows to compare and test an extracted watermark against the original signature.

Please refer to Marco Corvi's paper "Wavelet-based image watermarking for copyright protection", to get an idea about the algorithm.

OPTIONS

-a number
    Alpha factor that determines embedding strength of the signature. Allows to override the setting in the signature file.

-e number
    Wavelet filtering method for forward transformation. Allows to override the setting in the signature file.

-f number
    Wavelet filter number. Allows to override the setting in the signature file.

-F ffile
    Wavelet filter definition file. Allows to override the setting in the signature file.

-g number
    Wavelet filtering method for inverse transformation. Allows to override the setting in the signature file.

-h  Print a help message.

-o ofile
    Output watermarked image to the specified file instead of standard output.

-q number
    Set quantization/quality factor. Overrides the setting in the signature file.

-s sfile
    The signature file to embed into the input image. See gen_corvi_sig (1) for a description of the file format. Mandatory parameter. file Input image in PGM format to sign (watermark). Default: standard input.

-v number
    Verbosity level. Specify higher numbers for more informatative output. Default value: 0.

file
    The image in PGM format to be watermarked.

OUTPUT
The signed (watermarked) image in PGM format is written to standard output or, optionally, to ofile. The length of the signature (watermark) determines the level of the image residue (coarse image) where the signature is embedded.

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

AVAILABILITY
The most recent released version of 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.

SEE ALSO
gen_corvi_sig (1), wm_corvi_d (1), wm_corvi_s (1), cmp_corvi_sig (1)