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a TEXT file (218KB) |
a Word file (280KB) |
a PDF file (211KB) |
a JPEG file (2,110KB) |
Complexity histograms of a non-compressed and a compressed file
The figures below illustrate the "file-complexity histograms." Original files (that are non-compressed) have variety of histogram patterns (black curves), while the compressed files (by ZIP or LHA) tend to converge in a "normal distribution" pattern (red curve). It is known that a "random file's" histogram is approximated by a Normal Distribution having MeanVal=0.5, Stand. Dev=0.047. The compressed JPEG file below shows almost a random file pattern.
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a TEXT file (218KB) |
a Word file (280KB) |
a PDF file (211KB) |
a JPEG file (2,110KB) |
An embedding file (a file to be embedded) is compressed before embedding operation in BPCS-Steganography. The embedding operation starts from the LSB-plane and goes up to upper-planes in each color. Therefore, if the embedding operation stays only in a small amount, the image degradation after embedding will never be detectable by any means.
(Updated on Feb. 08, 2015 by Eiji Kawaguchi)