Patent ID: 7496210

Claim:
A method for steganalysis of an original image, comprising: obtaining a grey-scale image of the original image; generating a prediction-error image from the gray-scale image; computing three-level discrete wavelet transforms (DWTs) of both the gray-scale image and the prediction-error image; designating each of the gray-scale image and the prediction-error image as an LL 0 sub-band; computing histograms of LL 0 , LL i LH i , HL i and HH i sub-bands, where i=1, 2, 3, of the DWTs of both the gray-scale image and the prediction-error image; computing 1 st , 2 nd and 3 rd order moments for each of the sub-bands; combining the moments to extract features from both the gray-scale image and the prediction-error image; and analyzing the extracted features with a classifier configured to detect changes in the histograms of the sub-bands that indicate hidden data.