The Research Of Making Use Of Vector Quantization And Hiding Of Image Ciphered By DES

With the development of the technology, the quick development of themultimedia and network makes digital technology widely used in many fields. But thesecurity of the digital technology is facing more and more threatens, for example,media's copyright can't protect; software or documents were copied illegally and etc.;It is becoming very urgent to protect the right of knowledge from internet. Theinformation transferring and the information hiding have been attracted great attentionby many researchers because it provides digital information of security protected andtransportation secretly with a useful tool.This thesis mainly discussed the following three parts. Firstly, it introduces thebackground and significance of the information hiding, then introduces the theorymodel about the information hiding and examination .Secondly, introduces the theoryof vector quantization and the vector quantization machine based on the definition, sowe know that vector quantization can be considered as a space mapping to another.The vector quantization machine consists of encoders and decoders. An encoder isused to search the most suitable codeword from the codebook according to thedistortion measurement, and find out where is the input vector. When decoding, wecan rebuild the input image because the input vector can be found by looking up thecodebook. Also it introduces some important technology about the vectorquantization: the design of codebook, the searching of codeword, and different kindsof vector quantization. The third part introduces the DES encryption and describe theinside structure of DES and algorithm. Finally, we introduce the experiment result. We use the vector quantization tocompress the source image. Then we get the codebook and codeword, encrypt the data,and imbed them to the host image.We treat PEPPER as the host image, and LENA as the source image. The resultindicates this method is effective and can be put into practice, and achieve satisfactoryperformance.