JPEG2000 is a new international standard for still image compression. It provides various functions in one single coding stream and the better compression quality than the traditional JPEG, especially in the high compression ratio. However, the heavy computation and large internal memory requirement still restrict the consumer electronics applications. In this paper, we propose a QCB (quad code block)-based DWT method to achieve the higher parallelism than the traditional DWT approach of JPEG2000 coding process. Based on the QCB-based DWT engine, three code blocks can be completely generated after every fixed time slice recursively. Thus, the DWT and EBCOT processors can process simultaneously and the high computational EBCOT then has the higher parallelism of the JPEG2000 encoding system. By changing the output timing of the DWT process and parallelizing with EBCOT, the internal tile memory size can be reduced by a factor of 4. The memory access cycles between the internal tile memory and the code block memory also decrease with the smooth encoding flow.
- Code block
- Quad code block