The Application Of Wavelet Transform To Image Compression And Transmission

Wavelet transform is the development of Fourier transform, as a multi-resolution analysis method, wavelet, which has good characteristic of time-frequency and space-frequency ,is especially suitable for image coding based on human vision, and can be combined with embedded coding to perform progressive image transmission. Image compression and progressive image transmission based on wavelet transform can overcome some defects of JPEG technique which downloads image by row and has square-effect at low bit-rate.In this paper, the author mainly studies wavelet transform application to image compression and progressive image transmission. Firstly, the author introduces the basic theories of wavelet transform and basic techniques of image compression. Secondly, the author studies the schemes of image compression and progressive image transmission based on wavelet transform and EZW coding, and compares the experimental results based on the second generation wavelet transform with the experimental results based on the first generation wavelet transform. Finally, the author mainly studies the application of second generation wavelet transform to image compression and progressive image transmission, and improves some algorithms based on the previous products in this field: I ) A more convenient means of calculating ROI mask is proposed .II)A method that only selects some of wavelet coefficients of the ROI and background area to compress image .By comparing the experimental results ,the author concludes that this improvement is valid and can increase the quality of decoded image.