Many advanced image-processing softwares are available for tampering images. How to determine the authenticity of an image has become an urgent problem. Copy–move is one of the most common image forgery operations. Many methods have been proposed for copy–move forgery detection (CMFD). However, most of these methods are designed for grayscale images without any color information used. They are usually not suitable when the duplicated regions have little structure or have undergone various transforms. We propose a CMFD method using local geometrical color invariant features to detect duplicated regions. The method starts by calculating the color gradient of the inspected image. Then, we directly take the color gradient as the input for scale invariant features transform (SIFT) to extract color-SIFT descriptors. Finally, keypoints are matched and clustered before their geometrical relationship is estimated to expose the duplicated regions. We evaluate the detection performance and computational complexity of the proposed method together with several popular CMFD methods on a public database. Experimental results demonstrate the efficacy of the proposed method in detecting duplicated regions with various transforms and poor structure.
"Exposing region duplication through local geometrical color invariant features," Journal of Electronic Imaging 24(3), 033010 (21 May 2015). https://doi.org/10.1117/1.JEI.24.3.033010