Bit-Serial VLSI Implementation of Vector Quantizer for Real-Time Image Coding

Absrract -Vector quantization (VQ) has emerged as a viable approach for coding speech and image data in the last decade. Various vector quantizers are designed and their performance evaluated during the last few years. The hardware realizations of VQ encoder systems have been designed mainly for real-time speech coding ranging from the use of “off-the-shelf” components to applying VLSI technology. Real-time image coding requires much higher throughput rate compared to speech data. In this paper, a practical high throughput architecture and its implementation for real-time coding of TV quality signals is presented. The architecture is directed towards the implementation of multi-stage VQ as our simulation results (presented in this paper) show that it is more suitable for real-time coding. However, the implementation is suitable for both single-stage and multi-stage VQ. The functional blocks of the VQ encoder system have been designed and implemented in VLSI technology. The VQ encoding scheme designed has an encoding delay of 25 clock cycles and it is independent of the codebook sue.