Abstract
Digital forensics is now an important research topic, and camera source identification is a special issue in digital forensics. In this work, we try to analyze useful features on camera source identification. Interpolation coefficients of color demosaicking algorithm have been proved to be an effective feature to characterize cameras. Here, we address smooth and non-smooth separation issue while different regions in the image may use different interpolation coefficients. The modified EM algorithm will combine the smooth and non-smooth separation result to improve the identification result. Peak map produced by our modified EM algorithm is another characteristic on camera source identification. We will use different peak representation to test the identification results on each case. Moreover, we use principal component analysis (PCA) for dimension reduction which will speed up the training time. Finally, we use a support vector machine (SVM) to determine the source of each digital image.