Data Hiding on Digital Images by Diamond Encoding driven through JPW Masking

This paper proposes a new improved steganographic technique based on pixel value adjustment which is driven by Just Perceptual Weighting (JPW) masking[14]. The cover image is scanned using a spatial frequency and luminance mask (called as JPW masking) and the result is used as the candidate region to perform data hiding using diamond encoding method[15]. The process of embedding partitions the candidate region into non-overlapping blocks of two consecutive pixels and transforms the secret messages to a series of k-ary digits. For each block, the diamond encoding technique is applied to calculate the diamond characteristic value, and one secret k-ary digit is concealed into the diamond characteristic value. The diamond characteristic value is modified to secret digit and it can be obtained by adjusting pixel values in a block. This scheme is designed in such a way that the distortion of each block after diamond encoding is never out of the embedding parameter k, and the block capacity is equal to log2(2k2 + 2k + 1). In contrast to the existing methods based on LSB, the masking driven approach has lower distortion for various payloads. It is expected that the proposed method provides better performance than the existing techniques and also to be more secure to steganalysis techniques.