Realization Of Adaptive Block-based Image Sequence Compression

Digital video coding is the key technology of all kinds of digital video applications.In the past twenty years,digital video compression technology has made great progress and has accelerated the research and development of videophone and digital TV etc. There are two series video compression standards:ITU-T video coding standards H.26x (e.g. H.261, H.262, H.263 and H.26L/4) and ISO/IEC standards MPEG-x (e.g. MPEG-1, MPEG-2 and MPEG-4). In the beginning of the article, the development of digital video compression coding technology is introduced.H.26L/H.264 is a new video compression standard provided by ITU-T and ISO/IEC, which faces to very low rate video communication. It uses a new DCT transform method as 4*4 integer DCT. It can reduce block effect, while it is clear and easy to realizen, has high precision, computes fast and costs less memory. In this article, the transformation of 32 bits 4*4 integer DCT adopted by H.26L standard and 16 bits 4*4 integer DCT adopted by H.264 are particular narrated, the performance of them is compared and the improvement of current used video compression coding method is provided.One of the common characters between traditional algorithms based on DCT image coding is that regardless of the content of the image, they use a fixed size block to process, for example, JPEG, MPEG-1/2, H.263 use constant 8*8 block mode. The main work of this article is to propose a sequence images compression algorithm that is based on adaptive block dividing and object to the disadvantages of the one based on fixed-size block dividing. The proposed algorithm is an image compression method, which can auto-adjust DCT block size (8*8 or 4*4) according to the difference of corresponding blocks between two frames of the sequential image and doesn't process any unnecessary data blocks in order to enhance coding efficiency. Compared to traditional methods,it has better compress efficiency and effect. In this article, the two methods mentioned above are compared.Meanwhile, the method of software and hardware realization is also been proposed, so is the flowchart of this compress system. At last, the coding algorithm of...