Weighted stego-Image based steganalysis in multiple least significant bits

The paper proposes a method for LSB steganalysis of images, where the secret message is embedded in a given number L of the least significant bits. The proposed estimation method is based on weighted stego-Image and no assumption of cover images is required. The method can detect the presence of stego message using LSB steganography from the case L = 1 to arbitrary L≫1.The estimation formula is clean and computation complexity is low. To evaluate the proposed steganalytic method, two experiments of detection and estimation are performed. It is shown that the accuracy of detecting the existence of secret messages in images and of estimating the embedding ratio of secret messages is relatively high.