Mercurial > hg > wm
diff Meerwald-dir/wm_cox_e.1 @ 24:9f20bce6184e v0.7
move directories, support netpbm 11
author | Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
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date | Fri, 20 Dec 2024 13:08:59 +0100 |
parents | Meerwald/wm_cox_e.1@be303a3f5ea8 |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Meerwald-dir/wm_cox_e.1 Fri Dec 20 13:08:59 2024 +0100 @@ -0,0 +1,110 @@ +.\" +.\" wm_cox_e.1 - the *roff document processor man page source +.\" +.TH wm_cox_e 1 "98/07/01" "Watermarking, Version 1.0" +.SH NAME +.B wm_cox_e +\- a program to embed a signature in the DCT coefficients of an image +.SH SYNOPSIS +.B wm_cox_e +[ +.BI \-a \ number +] +[ +.B \-h +] +[ +.BI \-o \ ofile +] +[ +.BI \-q \ number +] +.BI \-s \ sfile +.I file +.SH DESCRIPTION +.B wm_cox_e +is a program to embed a signature (watermark) from +.I sfile +into the DCT coefficients 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_cox_sig +is used to generate a signature file, +.B wm_cox_d +extracts a signature from a watermarked image and +.B cmp_cox_sig +allows to compare and test an extracted watermark against the original +signature. +.PP +Please refer to Ingemar J. Cox's paper "Secure Spread Spectrum +Watermarking for Multimedia", 1995, 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 +.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_cox_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 +.I file +The input image in PGM format. +.PP +.SH OUTPUT +The signed (watermarked) image in PGM format is written to standard output +or, optionally, to +.I ofile. +The embedding process may take some time on large images since the DCT +is performed on the whole image in one step (not block-wise). +.PP +The +.I n +largest coefficients are pulsed to embed the +.I n +bit watermark. +.PP +.SH AUTHOR +Peter Meerwald. Email bug reports to pmeerw@cosy.sbg.ac.at. +.SH AVAILABILITY +The most recent released version of +.B wm_cox_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_cox_sig +(1), +.BR wm_cox_d +(1), +.BR cmp_cox_sig +(1)