comparison Meerwald/wm_cox_e.1 @ 0:be303a3f5ea8

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author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Sun, 12 Aug 2007 13:14:34 +0200
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1 .\"
2 .\" wm_cox_e.1 - the *roff document processor man page source
3 .\"
4 .TH wm_cox_e 1 "98/07/01" "Watermarking, Version 1.0"
5 .SH NAME
6 .B wm_cox_e
7 \- a program to embed a signature in the DCT coefficients of an image
8 .SH SYNOPSIS
9 .B wm_cox_e
10 [
11 .BI \-a \ number
12 ]
13 [
14 .B \-h
15 ]
16 [
17 .BI \-o \ ofile
18 ]
19 [
20 .BI \-q \ number
21 ]
22 .BI \-s \ sfile
23 .I file
24 .SH DESCRIPTION
25 .B wm_cox_e
26 is a program to embed a signature (watermark) from
27 .I sfile
28 into the DCT coefficients of an image
29 .I file
30 and output a signed (watermarked) image
31 .I ofile.
32 Both, input and output image,
33 are in PGM (portable graymap) format.
34 .PP
35 If
36 .I file
37 or
38 .I ofile
39 is not specified, then standard input or standard output is
40 used. The signature
41 .I sfile
42 is a mandatory parameter however.
43 .PP
44 .B gen_cox_sig
45 is used to generate a signature file,
46 .B wm_cox_d
47 extracts a signature from a watermarked image and
48 .B cmp_cox_sig
49 allows to compare and test an extracted watermark against the original
50 signature.
51 .PP
52 Please refer to Ingemar J. Cox's paper "Secure Spread Spectrum
53 Watermarking for Multimedia", 1995, to get an idea about the algorithm.
54 .PP
55 .SH OPTIONS
56 .TP
57 .BI \-a \ number
58 Alpha factor that determines embedding strength of the signature.
59 Allows to override the setting in the signature file.
60 .TP
61 .B \-h
62 Print a help message.
63 .TP
64 .BI \-o \ ofile
65 Output watermarked image to the specified
66 .I file
67 instead of standard output.
68 .TP
69 .BI \-q \ number
70 Set quantization/quality factor. Overrides the setting in the signature
71 file.
72 .TP
73 .BI \-s \ sfile
74 The signature file to embed into the input image. See
75 .B gen_cox_sig
76 (1) for a description of the file format. Mandatory parameter.
77 .IR file
78 Input image in PGM format to sign (watermark). Default: standard input.
79 .TP
80 .I file
81 The input image in PGM format.
82 .PP
83 .SH OUTPUT
84 The signed (watermarked) image in PGM format is written to standard output
85 or, optionally, to
86 .I ofile.
87 The embedding process may take some time on large images since the DCT
88 is performed on the whole image in one step (not block-wise).
89 .PP
90 The
91 .I n
92 largest coefficients are pulsed to embed the
93 .I n
94 bit watermark.
95 .PP
96 .SH AUTHOR
97 Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at.
98 .SH AVAILABILITY
99 The most recent released version of
100 .B wm_cox_e
101 is always available
102 at http://www.cosy.sbg.ac.at/~pmeerw/Watermarking or via anonymous ftp from ftp.cosy.sbg.ac.at in the
103 directory /pub/people/pmeerw/Watermarking.
104 .SH "SEE ALSO"
105 .BR gen_cox_sig
106 (1),
107 .BR wm_cox_d
108 (1),
109 .BR cmp_cox_sig
110 (1)

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.