Image Steganography Using Remainder Replacement, Adaptive QVD and QVC

This research article reports a steganography method based on adaptive quotient value differencing (AQVD), quotient value correlation (QVC), and remainder replacement. It possesses two advantages, (i) avoids unused pixel blocks problem, and (ii) performs data integrity verification at the receiver. It accomplishes data camouflaging and retrieval on 3-by-3 disjoint pixel blocks. From a 3-by-3 size pixel block three new blocks are derived, (i) quotient (QT) block, (ii) middle bit (M) block and (iii) remainder (R) block. A quotient of the quotient block is decimal equivalent of six binary bits. AQVD procedure is enforced to hide data in 4 corner quotients of the quotient block. The top-middle and bottom-middle quotients are appraised as reference values for AQVD procedure. In left-middle, center, and right-middle quotients, QVC embedding procedure is plied for data camouflaging by using their respective top and below neighbors as reference values. The 7th bit forms the M block and the 8th bit (least significant bit) forms the R block. Secret bits are camouflaged in M block by bit substitution. The verification bits are computed from QT block and M block. The verification bits are stored at R block, so that at the receiver side the integrity of the pulled-out bits can be checked. The experimental results prove that the recorded HC and PSNR values are improved. Furthermore, regular-singular (RS) and pixel difference histogram (PDH) analyses could not detect this technique.