Research And Improvement Of The Image Compression Algorithm Based On SPIHT

With the development of technology in the multimedia and digital image, how to effectively store and quickly transmit the image becomes more and more important. Because image information contains a huge amount of the data,therefore, it is necessary to compress the image for reducing the image storage space and accelerating the image transmission. At present, the wavelet transformation based on its good time frequency partial characteristic, has widely research and application in image compression domain.This paper deeply analyzes the embedded zerotree wavelet algorithm and SPIHT algorithm which is based on the EZW. As the same time, according to the deficiencies of the SPIHT algorithm, this paper improved a method based on SPIHT. The improving method is according to the different between high frequency zone and low frequency zone, it can be division different blocks, each block according to its own maximum coefficient defined initial threshold,Thus, to complete each block scan operation. At the last of this paper,experiments results prove that, the improved coding method reduced encoding time, as the same time, the image compression quality is allowed.