Steganalysis of ±k Steganography based on Noncausal Linear Predictor

摘要

The paper proposes a novel steganalytic technique for ±k steganographybased on noncausal linear predictor using prediction coefficients obtained from the autocorrelationmatrix for a block of pixels in the stego-image. The image is divided intoequal-size blocks, autocorrelation matrix is found for the block, and the appropriatenoncausal linear prediction coefficients is selected to predict all pixels in that block. Apixel is assumed to be embedded with message bit if the absolute difference betweenthe original pixel value and predicted pixel value exceeds the pre-defined threshold.The effectiveness of the proposed technique is verified using different images.