Mercurial > hg > wm
diff Meerwald-dir/wm_koch_e.1 @ 24:9f20bce6184e v0.7
move directories, support netpbm 11
author | Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
---|---|
date | Fri, 20 Dec 2024 13:08:59 +0100 |
parents | Meerwald/wm_koch_e.1@be303a3f5ea8 |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Meerwald-dir/wm_koch_e.1 Fri Dec 20 13:08:59 2024 +0100 @@ -0,0 +1,98 @@ +.\" +.\" wm_koch_e.1 - the *roff document processor man page source +.\" +.TH wm_koch_e 1 "98/07/05" "Watermarking, Version 1.0" +.SH NAME +.B wm_koch_e +\- a program to embed signature bits in the DCT coefficients of an image +.SH SYNOPSIS +.B wm_koch_e +[ +.B \-h +] +[ +.BI \-o \ ofile +] +[ +.BI \-q \ number +] +[ +.BI \-v \ number +] +.BI \-s \ sfile +.IR file +.SH DESCRIPTION +.B wm_koch_e +is a program to embed signature bits in 8x8 DCT coefficients of +an image. The signature has to be generated by the +.B gen_koch_sig +program. The +.B wm_koch_d +program is used to extract a signature from a signed (watermarked) image. The +.B cmp_koch_sig +program compares and tests the extracted signature against the original signature. +.PP +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 +Please refer to E. Koch's paper "Towards Robust and Hidden +Image Copyright", 1995, to get an idea about the algorithm. +.PP +.SH OPTIONS +.TP +.B \-h +Print a help message. +.TP +.BI \-o \ ofile +Output signed (watermarked) image to +.I ofile +instead of standard output. +.TP +.BI \-q \ number +Quality/robustness factor used to embed signature into image. +Overrides setting from signature file. +.TP +.BI \-s \ sfile +The signature file to embed into image. See +.B gen_koch_sig +(1) for a description of the file format. Mandatory parameter. +.TP +.BI \-v \ number +Verbosity level. 0 for quiet operation, higher numbers for more +output. Default value: 0. +.TP +.IR file +Input image in PGM format to sign (watermark). Default: standard input. +.PP +.SH OUTPUT +The signed (watermarked) image in PGM format is written to standard output +or, optionally, to +.I ofile. +.PP +Two coefficients of an 8x8 DCT block are selected at random to embed a +single signature bit. +.PP +.SH AUTHOR +Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at. +.SH AVAILABILITY +The most recent released version of +.B wm_koch_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_koch_sig +(1), +.BR wm_koch_d +(1), +.BR cmp_koch_sig +(1)