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Phil Sallee's MATLAB JPEG Toolbox
The Matlab's built-in functions used to
handle digital images provide only basic
conversion between the given JPEG file and
image pixels. Thus, they are not effective
in dealing with a DCT-based steganographic
method since there is no access to the qDCT
coefficients. To overcome this issue, we use
a dedicated Matlab JPEG Toolbox developed by
Phil Sallee. The Sallee's Toolbox contains
special functions allowing to access and
manipulate the qDCT coefficients of a given
JPEG file.
The main two functions in the package of
Sallee "jpeg_read" and "jpeg_write" perform
the steps of the lossless compression
applied to the qDCT coefficients, including
Huffman coding and decoding. Thus, they
provide more functionality, since they give
the ability to gain direct access to all the
structural elements of a JPEG file from
Matlab, including the matrices of qDCT
coefficients and the quantization tables.
Phil Sallee's ORIGINAL
Toolbox:
This package is the original one;
jpegtbx_1.4.zip. It includes several functions
for handling jpeg images, including the two main
functions for reading and writing jpeg files. In
addition to Matlab functions (m files), the
package includes pre-compiled MEX binaries files
(.dll) working under 32-bit systems.
http://dde.binghamton.edu/download/jpeg_toolbox.zip:
This package
is based on the original one and provided by the
Digital Data Embedding Laboratory at Binghamton
University in New York. It includes pre-compiled
MEX binaries for 32-bit and 64-bit systems for
several operating systems.
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