Entropy CODEC from behavioral description based LSI-CAD for fully programmable image coding system

Entropy coding, as used for lossless compression in image coding, is dominated by serial bit processing on variable wordlength data. Digital signal processors (DSPs), in which pipeline processors play a central role, fail to yield adequate performance for this kind of application. This paper proposes a new approach that fulfills the two requirements for bit processing, the dominant task in entropy coding: high-performance and functional flexibility. This approach is based on Amphibious logic combining a high-level design LSI-CAD system with a functionally reconfigurable Field Programmable Gate Array (FPGA). Functions are programmed via a behavioral description program in a high-level design LSI-CAD system. In order to show the effectiveness of the newly proposed Amphibious logic approach, we designed JPEG-type Huffman and arithmetic CODECs for encoding still images. A comparison with the results of the processing speeds of DSPs and general-purpose microprocessors proves that the Amphibious logic is indeed possible to attain the dual goals of high performance and programmability. The proposed approach can be used to augment a conventional DSP by allocating the functions of numerical processing and bit stream processing, as used in image coding algorithms, between DSPs and FPGAs.