Universal JPEG steganalysis based on special frequency regions from wavelet transform

This article has presented a new steganalysis method based on wavelet transform. First, wavelet transform is applied on the original image to separate different frequencies subbands. Then, for greater focus on frequency regions, the blocking technique is carried out on these subbands and they are divided into equal sized sectors. Afterwards, optimal wavelet packet transform method is applied in feature extraction stage. Entropy cost function of coefficients is modified with message embedding and tends to be zero. As a result, the ultimate optimal tree having the maximum number of necessary nodes can be built. Experimental results indicate that the ultimate obtained features are a good basis to detect a secret message in the image.