Research And Imjplementation Of The Technology For Digital Image Compression And Enciyption

With the fast development of network and multimedia, the security and efficiencyof image data transmission has been gaining more and more attention. So the digitalimage compression and encryption technology have been born. This paper mainlydiscusses the image compression coding algorithm that is based on wavelet transformand the image encryption algorithm based on chaos theory. The main contents of theresearch can be summarized as the following aspects:1. The embedded coding algorithm based on wavelet-tree, including EmbeddedZerotrees Wavelet algorithm and Set Partitioning in Hierarchical Trees algorithm, isstudied in detail. In order to achieve higher compression ratio, we combine EZWalgorithm and adaptive arithmetic coding algorithm to implement an image compressionsystem. In addition, on the basis of the analysis of the SPIHT principle, improvement ismade to reduce memory consumption and enhance the algorithm’s efficiency.2. A new image encryption algorithm based on chaotic systems is presented. In thenew algorithm, the position of image pixels is scrambled by a standard chaos map. Andthe value of image pixels is changed by a XOR matrix which is generated by theLogistic Mapping. The simulation results show that the proposed encryption algorithmis valid.3. A digital image content protection system is realized by an image encryptionmethod in which the compressed image code stream and a random sequence generatedby Logistic mapping will be the bitwise XOR. The software running results show thatthe method has good encryption effect and can ensure the image transmission safe.