The Study Of Digital Image Compression Technology Based On Wavelet Transform

Image information is an important head spring for people to know the world and ourselves. But the data quantity of image is huge, which not only requires high storing and operating capacity for computers, but also restricts the channel transfer rate of image communication. Therefore, in order to store, process and transfer the data, compress processing must be done for image information. This paper discusses it in such condition.The main content of the thesis is implementation of image compression by wavelet transform. The basic framework is that, firstly, a brief introduction about image compression theory and the important of image compression, and in accordance with the current and future developing trend of image compression, it is believed that wavelet transform will become to be the main technology in image data compression because of its peculiar feature, it is followed by the brief introduction of classic wavelet transform theory and its application in image compression. The history and hardware characteristic of DSP were introduced, then based on analysis for the hardware characteristic of the chip TMS320VC5409, an image compression platform is proposed, design of the DSP system circuit and the peripheral equipment circuits are studied too. The wavelet transform is realized by lifting algorithm, using a new fast DWT lifting algorithm which separates the stretch changes steps and lifting steps, realize to reduce operation times of computer's arithmetic.Finally, in accordance with an standard test image, and the compressed image is compared by JPEG compression method and DWT compression method through MATLAB simulation, the ending indicate the wavelet transform image compression method is very feasible and useful.