Model-based JPEG Steganography Demo

Phil Sallee


This demo consists of Matlab routines which implement the JPEG steganography method described in the paper entitled "Model-Based Steganography", presented at the International Workshop on Digital Watermarking in October, 2003. A preprint of the paper is available here.

These routines require the Matlab JPEG Toolbox, available here.

The following Matlab functions are included in this distribution:
arith_decode           	  Non-adaptive arithmetic decoder
arith_encode           	  Non-adaptive arithmetic encoder
blockiness             	  Calculate blockiness statistic for a JPEG image
deblock_delta          	  Compute a delta image that will reduce blockiness
get_sym_frq            	  Obtain symbols and model frequencies for coefficients
get_sym_val            	  Convert symbols to coefficient values
jpeg_steg_capacity     	  Estimate capacity of a JPEG image
jpeg_steg_decode       	  JPEG steganography decoder (used for MB1 and MB2)
jpeg_steg_encode       	  JPEG steganography encoder (MB1)
jpeg_steg_encode_deblock  JPEG steganograhpy encoder with deblocking (MB2)
mcdf                   	  Model cumulative density function
mcdfinv                	  Model inverse cumulative density function
mfit                   	  Maximum likelihood model parameter estimate
mfitc                  	  Maximum likelihood model parameter estimate (center bin)
mpdf                   	  Model probability density function
mrand                  	  Draw samples from model distribution
showimage              	  Display an image at the correct resolution
steg_decode            	  Generic steganography decoder
steg_encode            	  Generic steganography encoder
stegtest                  Demonstration script for MB1
stegtest_deblock          Demonstration script for MB2
This software is free for educational and non-profit use. See the README file for licensing information.

Download:

Gzipped tar file (64k, mbsteg_1.2.tar.gz)
PKZip archive (72k, mbsteg_1.2.zip)
README file (6k, README)