ABSTRACT
PROJECT OUTPUT
Hiding capacity is very important for efficient covert communications. For JPEG2000 compressed images, it is necessary to enlarge the hiding capacity because the available redundancy is very limited. In addition, the bitstream truncation makes it difficult to hide information. In this paper, a high-capacity steganography scheme is proposed for the JPEG2000 baseline system, which uses bit-plane encoding procedure twice to solve the problem due to bitstream truncation. Moreover, embedding points and their intensity are determined in a well defined quantitative manner via redundancy evaluation to increase hiding capacity. The redundancy is measured by bit, which is different from conventional methods which adjust the embedding intensity by multiplying a visual masking factor. High volumetric data is embedded into bit-planes as low as possible to keep message integrality, but at the cost of an extra bit-plane encoding procedure and slightly changed compression ratio. The proposed method can be easily integrated into the JPEG2000 image coder, and the produced stego-bitstream can be decoded normally. Simulation shows that the proposed method is feasible, effective, and secure.
In JPEG coding system, quantized DCT coefficients are entropy encoded without distortion to get the final compressed bitstream. Secure information hiding can be achieved simply by modification on the quantized DCT coefficients. A DCT domain hiding scheme can be applied in JPEG very conveniently. There have been many kinds of DCT domain information hiding schemes developed for JPEG standard, such as the above-mentioned J-Steg, JPHide-Seek, and OutGuess. However, the situation is quite different for JPEG2000. As the latest still image coding international standard, JPEG2000 is based on discrete wavelet transform (DWT) and embedded block coding and optimized truncation (EBCOT) algorithms. It offers superior compression performance to JPEG, and puts emphasis on scalable compressed representations. In JPEG2000 coding system, bitstream is rate-distortion optimizing truncated after bit-plane encoding. The secret message will be destroyed by the truncating operation if it is embedded directly into the lowest bit-plane of quantized wavelet coefficients. Although there exist many kinds of DWT domain hiding schemes, most of them can not be fitted into JPEG2000 directly.
PROJECT OUTPUT
Contact:
Mr. Roshan P. Helonde
Mobile: +91-7276355704
WhatsApp: +91-7276355704
Email: roshanphelonde@rediffmail.com
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