Rate insensitive steganalysis of ±1 embedding in images

We present a rate insensitive method for detecting steganography using plusmn1 embedding. plusmn1 embedding is generally considered to be difficult to detect. In prior work, we developed a high performing method based on statistics computed by a lossless image compressor. However, the method suffered a weakness that the embedding rate needed to be known. In this work, we introduce improved classifiers that work without knowing the rate. The overall classification rate is excellent for the database of images studied.