Revealing image forgery through image manipulation detection

Digital images have a very significant role in various fields like medical imaging, journalism, criminal and forensic investigations. Because of the widespread availability of photo editing software and tools, it becomes problematic to use the digital images in applications where their genuineness is of prime importance. Therefore, it is necessary to create forensic techniques which are capable of detecting the tampering in image. Most common operations that are involved in the creation of forged images are contrast enhancement, copy-paste forgery etc. In this paper, we present different techniques for detecting global contrast enhancement and copy-paste forgery. The proposed technique for the detection of contrast-enhanced image is based on contrast calculation. The technique is found to be robust against the JPEG compression as post-processing operation. In copy-paste forgery detection, we used DCT based feature extraction method. The technique can efficiently detect the small, medium and large size regions in the forged image.