It has been noticed that the block artifact grids (BAG), caused by the blocking processing during JPEG compression, are usually mismatched when interpolating or concealing objects by copy-paste operations.
An algorithm had been developed to extract BAGs to judge whether there are mismatches.
· Duplicated regions detect:
There are two key-problems in scaled/rotated duplicated regions detection. One is the features should be scale/rotatioin robust, and the other is how to classify vectors corresponding to matching pairs.
A vector erosion filter is designed to solve the vector mismatching problem.
· Tensor analysis:
All photos experence software processings, both in the camera and by processing softwares (such as Adobe Photoshop). Each processing cause a change in photo space, and many of them collapse photo space to a sparse space. The rule about a special sparse space corresponds to a series special processings.
With tensor decomposition, we find a way to express the space rule via residule, and a processing history classifier is developed.
