Exponential-Golomb coding

Abstract: The invention discloses a method for coding a hybrid image efficiently. The method comprises the following steps of: applying base color and an index table coding method to interframe coding of the hybrid image; sequencing a base color value obtained by clustering matching blocks and a base color value obtained by clustering the current coding blocks during transmission of the base color; correspondingly making a difference to obtain a residual value of the base color; transmitting a difference value by using exponential Golomb coding; adaptively selecting a transmission mode of the base color by taking the minimum code rate as a principle and adopting an equal length coding method of the base color during the transmission of the base color; marking the transmission code with a bite; and obtaining a base color index of each pixel in a prediction block according to the value of each pixel in the prediction block, the base color value of the current coding block and the principle of minimum Euclidean distance during the transmission of an index map, taking the base color index of each pixel as a reference index of the current coding block, and using a bite for showing whether the index of each pixel is matched with the reference index of a corresponding position.

Abstract: This paper presents a novel method for the real-time protection of new emerging High Efficiency Video Coding (HEVC) standard. Structure preserving selective encryption is being performed in CABAC entropy coding module of HEVC, which is significantly different from CABAC entropy coding of H.264/AVC. In CABAC of HEVC, exponential Golomb coding is replaced by truncated Rice (TR) up to a specific value for binarization of transform coefficients. Selective encryption is performed using AES cipher in cipher feedback mode on a plaintext of binstrings in a context aware manner. The encrypted bitstream has exactly the same bit-rate and is format complaint. Experimental evaluation and security analysis of the proposed algorithm is performed on several benchmark video sequences containing different combinations of motion, texture and objects.

Abstract: The embodiment of the invention discloses an H.264_advanced video coding (AVC)-video-stream-integrity-based fragile watermark authentication method, which comprises the following steps of: replacing a corresponding codeword by adopting adaptive variable length coding and exponential Golomb coding in an H.264_AVC compressed bit stream to embed watermark information; resolving the H.264 slice-level compressed bit stream, and performing decoding to generate a feature code according to a key; resolving a macro block-level bit stream and extracting watermark; and performing integrity authentication on a video frame according to the decrypted feature code and the extracted watermark. By the method, the watermark is embedded and extracted based on the compressed bit stream, so the method is low in computational complexity and relatively more practical; after the watermark is embedded, the length of the codeword is unchanged, and video distortion is relatively lower; and the rapid extraction of the watermark can be realized, and the requirements of real-time video processing can be met.

Abstract: This paper proposes an application-domain specific instruction-set processor (ASIP) with dedicated instructions for lossless data compression and decompression process to be used in artificial vision systems. Proposed ASIP has dedicated instructions to accelerate the performance to codec operations of Exponential Golomb coding, where the coding parameter value can be set by the user in order to maximize the compression ratio. Experimental results through simulation show that the proposed ASIP reduces execution cycles by 88% for compression and 42% for decompression, and reduces energy consumption by 85% for compression and 40% for decompression, compared with the base reduced instruction set computer processor.