Abstract: Abstract: Block-DCT based information embedding methods introduce distinctive non-stationarites into the stego-image, which makes the difference distributions between neighboring pixel intensities in one block and across two blocks. While In the cover image these two distributions are indeed remarkably similar. So we used Kolomogrov-smirnov test on these two neighboring pixel populations to test binary hypothesis. In order to improve detective ability; we add absolute value and 8-domain to pairs of neighboring pixel. Theories and experiments both prove that our method is efficiency.