Research On Passive Image Forensics Algorithm Based On Copy And Paste Tampering

With the development of science and technology, digital image data become the important message carrier, has been widely used in news reports, medical testing and science researching. However, due to the digital image processing technology and computer image processing software functions become powerful, more and more non-professionals can be easily tampered with the images contents. The integrality and reality of digital images are difficult to judge. Nowadays, digital image forensics is still in development stage, many key technologies are at the beginning of the study.At the same time, the digital manipulation technology has growing fast. This is undoubtedly bring a lot of obstacles to digital image forensics. Therefore, the digital image forensics technology researching become particularly important, and it become a hot research topic at present.In this paper, we firstly reviewed the digital image forensics technology and some typical image forgery methods. In view of the nature of digital image copy-move forgery,we propose a image detection algorithm for Copy-move forgery based on the discrete wavelet transform and singular value decomposition. In this method, low-frequency sub-band wavelet decomposition which is best approximation of the image is extracted,then decomposed by singular value decomposition, obtaining image feature vector.Calculated the Euclidean distance between the feature vector to detect the similar blocks.The experiments demonstrate that the proposed approach can greatly reduce the size of the image and the feature vector and accordingly increased detection efficiency of the matching block and had better robustness against noising and compression.