Efficient Data Hiding With Plus-Minus One or Two

In steganographic applications, the data-hiders always pursue good rate-distortion performance. A novel steganographic scheme with the allowable modifications {-2, -1, 0, +1, +2 } is proposed, in which the secret data are embedded into the least significant bits (LSB), second LSB and third LSB of cover samples using a triple-layered construction. When embedding secret data into the LSB, the cover samples that should be modified by one are located. In the second LSB embedding, adding one or subtracting one for the located samples are determined, and the samples that should be modified by two are chosen. With data-embedding in the third LSB, the selections of addition or subtraction of two at the suitable samples are made. This way, a family of data-hiding methods can be generated, and their rate-distortion performance approaches the theoretical upper bound.