Design of a low-power real-time wavelet CODEC circuit

This paper presents the architecture and design of a CODEC circuit that can compress and reconstruct 4:2:2 color VGA video images using two-dimensional DWT. For real-time operation and low-power consumption, we modified the traditional Mallat's sub-band coding method to reduce the amount of computation required in two-dimensional DWT. Using the modified method, two-dimensional DWT can be performed by two sets of one-dimensional DWT operations regardless of the number of decomposition levels. We adopted the systolic array architecture to design the circuit implementing our method. Our low-power real-time CODEC circuit was designed using Verilog HDL and fabricated as a VLSI chip using 0.35 μm 3.3 V CMOS standard cell process. We made a simple DVR system using our CODEC chip to store and retrieve the video image data to and from the hard disk, and observed successful real-time operations.