Improved tampering detection using color filter array characteristic
Xueming Li · Computer Engineering and Applications Journal · 2009
With the advent of image editing software,digital image can be easily manipulated and altered.If the image is tampered maliciously,the consequence may be very serious.So the detection of image tampering has become more and more important.Most digital cameras employ a single sensor and a color filter array,and then interpolate the missing color samples to obtain a color image.The interpolation introduces specific correlations and the correlations may be destroyed by the image tampering.EM algorithm can be used to analyze the correlations.Through the improvement of the existing model,the Gaussian distribution of the residual error is supplanted by the Laplace distribution in order to approach the real distribution.The results of experiment show that this approach can reveal traces of digital tampering in color images interpolated with different algorithms and the improved model can speed up convergence of EM algorithm and reduce the detecting time.