Energy deviation measure: a technique for digital image forensics

Digital image forgery and its forensics have emerged as a significant research domain. Digital forensics is required to examine the questioned images and classify them as authentic or tampered. This paper aims at image tamper detection using a novel energy deviation measure (EDM). The EDM is a measure of deviation in pixel intensity with respect to its immediate and distant neighbourhood. It is extracted by measuring the inter pixel intensity difference across and inside the DCT block boundary of a JPEG image. Features from EDM have been used for the classification of the authentic and tampered images. Support vector machine is used for image classification. The experimental results have shown that the proposed method performs better with fewer dimensions as compared to other state of the art methods. It gives improved accuracy and area under curve while classifying images. It is robust to noise and JPEG image compression quality factor.