Still Image Compression Algorithm Based On Wavelet Zerotree

With the rapid development of multimedia technology in recent years, the digital image transmission plays a very important role in communication fields. Digital images generally include a great deal of information, so the compression technology becomes the key of the research. On this occasion, it inevitably becomes one of the main tasks to seek after the effective image coding algorithm. The theory of wavelet transform is a new math branch developed in recent years. Because of its special characteristics in space-frequency, it has become one of the main research directions in image compression coding. This algorithm is a new image coding algorithm after the Fourier transform and the DCT transform. It divides the image into several subbands in different resolution and different direction, which are compatible with human visual characters. Besides, it can split image energy into some subbands so as to code, and make transform to the whole image, which is better than the DCT transform.Firstly, it introduces the basic principle of the image compression coding and the standard of JEPG still image compression. And make sure the gist of study direction.Then, by experiment we compare the basic principle of JPEG compression standard with that of JPEG2000 still image international compression standard. And some core techniques of JEPG2000 standard are elaborated particular such as EBCOT algorithm and ROI coding.Thirdly, it introduces elementary wavelet theory, the resources of it and the formula for transform. Then discuss its advantages in the field of image coding, its appraise standard of wavelet on image compression, combine the face apply, and choose the propriety wavelet.Next, the technology of wavelet zerotree is introduced, analyze two kinds ofclassical image coding algorithm based on wavelet zerotree idea------EZW and SPIHT.On the basis of them, an improved algorithm is proposed. The algorithm combines the...