Abstract: An effective data hiding method for binary images divides the cover image into 2-by-2 blocks and embeds 1 bit in each edge block by making use of the parity of the blocksum. In this paper a steganalytic scheme is described again st this technique. The proposed scheme uses difference between histograms of the blocksum when the block border is changed. By removing the top row and the left-most column to crop the suspected image, a test embedding is performed. This is used for estimating the initial embedding rate. Simulation results show that the proposed method can provide a satisfactory estimate of the embedding capacity.

Key words: block histogram , steganalysis, data hiding