摘要：
Due to rapid advances and availabilities of powerful image processing software, digital images are easy to manipulate
and modify for ordinary people. This makes it more and more difficult for a viewer to check the authenticity of a
given digital image. For digital photographs to be used as evidence in law issues or to be circulated in mass media, it is inevitably
needed to identify whether an image is authentic or not. In this paper, we discuss the techniques of copy-cover
image forgery and compare four detection methods for copy-cover forgery detection, which are based on PCA, DCT, spatial
domain, and statistical domain. We investigate their effectiveness and sensitivity under the influences of Gaussian
blurring and lossy JPEG compressions. It is concluded that the PCA method outperforms the others in terms of time complexity
and accuracy. In JPEG compression simulation, its true positive rate is above 90% and false positive rate is above
99%. In Gaussian blurring simulation, its true positive rate is above 77% and false positive rate is above 99%.
