Based On Of Mcf5272 The Jpeg Decoding Algorithm Design And Realization

With the growth of technology we have entered the digital age, the solution of dealing with multimedia data is often to compress data before its storage and transmission, and decompress it at the receiver for playing back. The accessibility of powerful and low-cost digital signal processing hardware and software has opened up this technology to many sections. Digital signal processor (DSP) is more suitable for digital signal processing than general CPU.Thus there will be of great benefit to employ DSP to real-time image decoder. In the dissertation, the principle of image coding, the JPEG system and the real-time signal processing system based on DSP are introduced first. Then the design of a JPEG real-time image decoder system based on Motorola ColdFire MCF5272 is discussed. The system is composed with six sections which are entropy decoder, inverse Z transform, inverse quantization, inverse discrete cosine transform (IDCT), up sampling and color space transform. Combining the principles of pipelining and parallelism of DSP with IDCT theory, we concentrate on the use of Multiply-Accumulate Unit of MCF5272 by merging the operations of addition and multiplication, and realize two dimension of IDCT with one dimension of IDCT efficiently. Testing shows the software meets the requirement of real-time decoder.