When using digital camera to get natural image

there exists CFA interpolation effect

it makes great correlation between three color channels. Propose a novel method to detect tampering operation using correlation between nature image color channels. Firstly

use method of posterior probability to build model for each color channel to accurately estimate noise generated by CFA interpolation; then

use Gaussian filter for filtering and extract CFA interpolation features; finally

classify according to extracted features and locate tampering area.Experimental results show that the proposed algorithm can effectively detect tampering image and locate.