Blind Steganalysis Based on Multi- resolution Transforms

Zohourian, Mehdi | 2012

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43461 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Ghaemmaghami, Shahrokh; Gholampour, Iman
  7. Abstract:
  8. Blind image steganalysis is a technique used for detecting the existence of the data hidden in an image, where no information about the stenographic algorithm is available or usable. In this way, an important problem is to find sensitive features which make noticeable statistical distinction between cover and stego images. New steganalysis methods based on multi-resolution transform, specifically the wavelet and the contourlet transforms, have been proposed in this thesis in order to enhance the detection accuracy of system especially at low embedding rates. In fact, multi-resolution transforms are powerful space-frequency analysis tools that have been found quite successful in detection of statistical changes made to the image by the embedding process. First, in this work, new scheme based on characteristics function of contourlet coefficients is proposed. Mathematical arguments as well as experimental results show the significant improvement achieved using the proposed scheme, as compared to some well-known universal image steganalysis methods. Next, another scheme is developed based on combining the statistics of singular values of wavelet coefficients with the 274-D feature set of Fridrich known as a sensitive DCT (Discrete Cosine Transform) feature set. It is shown based on analysis and simulations that the performance of the proposed method is superior to that of current methods for resistant JPG steganography methods like PQ (Perturbed Quantization)about 8%, especially at low embedding rates steganography.
  9. Keywords:
  10. Wavelet Transform ; Contourlet Transform ; Eigenvalue Decomposition ; Blind Watermarking ; Multiresolution Transform

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