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1 .\"
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2 .\" wm_koch_e.1 - the *roff document processor man page source
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3 .\"
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4 .TH wm_koch_e 1 "98/07/05" "Watermarking, Version 1.0"
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5 .SH NAME
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6 .B wm_koch_e
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7 \- a program to embed signature bits in the DCT coefficients of an image
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8 .SH SYNOPSIS
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9 .B wm_koch_e
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10 [
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11 .B \-h
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12 ]
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13 [
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14 .BI \-o \ ofile
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15 ]
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16 [
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17 .BI \-q \ number
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18 ]
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19 [
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20 .BI \-v \ number
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21 ]
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22 .BI \-s \ sfile
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23 .IR file
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24 .SH DESCRIPTION
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25 .B wm_koch_e
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26 is a program to embed signature bits in 8x8 DCT coefficients of
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27 an image. The signature has to be generated by the
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28 .B gen_koch_sig
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29 program. The
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30 .B wm_koch_d
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31 program is used to extract a signature from a signed (watermarked) image. The
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32 .B cmp_koch_sig
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33 program compares and tests the extracted signature against the original signature.
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34 .PP
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35 Both, input and output image,
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36 are in PGM (portable graymap) format.
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37 .PP
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38 If
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39 .I file
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40 or
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41 .I ofile
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42 is not specified, then standard input or standard output is
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43 used. The signature
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44 .I sfile
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45 is a mandatory parameter however.
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46 .PP
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47 Please refer to E. Koch's paper "Towards Robust and Hidden
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48 Image Copyright", 1995, to get an idea about the algorithm.
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49 .PP
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50 .SH OPTIONS
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51 .TP
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52 .B \-h
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53 Print a help message.
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54 .TP
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55 .BI \-o \ ofile
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56 Output signed (watermarked) image to
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57 .I ofile
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58 instead of standard output.
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59 .TP
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60 .BI \-q \ number
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61 Quality/robustness factor used to embed signature into image.
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62 Overrides setting from signature file.
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63 .TP
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64 .BI \-s \ sfile
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65 The signature file to embed into image. See
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66 .B gen_koch_sig
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67 (1) for a description of the file format. Mandatory parameter.
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68 .TP
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69 .BI \-v \ number
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70 Verbosity level. 0 for quiet operation, higher numbers for more
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71 output. Default value: 0.
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72 .TP
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73 .IR file
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74 Input image in PGM format to sign (watermark). Default: standard input.
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75 .PP
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76 .SH OUTPUT
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77 The signed (watermarked) image in PGM format is written to standard output
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78 or, optionally, to
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79 .I ofile.
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80 .PP
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81 Two coefficients of an 8x8 DCT block are selected at random to embed a
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82 single signature bit.
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83 .PP
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84 .SH AUTHOR
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85 Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at.
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86 .SH AVAILABILITY
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87 The most recent released version of
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88 .B wm_koch_e
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89 is always available
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90 at http://www.cosy.sbg.ac.at/~pmeerw/Watermarking or via anonymous ftp from ftp.cosy.sbg.ac.at in the
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91 directory /pub/people/pmeerw/Watermarking.
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92 .SH "SEE ALSO"
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93 .BR gen_koch_sig
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94 (1),
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95 .BR wm_koch_d
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96 (1),
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97 .BR cmp_koch_sig
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98 (1)
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