An improved approach to detecting content-aware scaling-based tampering in JPEG images

Content-aware scaling is a method for image retargeting. It has been widely used in image manipulation including tampering. To improve the detection of the forgery in JPEG images, we propose to merge calibrated neighboring joint density and a rich models-based approach that was originally designed for steganalysis. A feature selection algorithm is utilized to reduce the feature dimensionality in the merged feature set. Experimental results show that the high-dimensional detector consisting of calibrated neighboring joint density and rich model features noticeably improves the detection accuracy; and the application of feature selection method to the high-dimensional detector can further improve the detection accuracy by using a much smaller and optimized feature set.