A Semi-fragile Reversible Data Hiding by Coefficient-Bias Algorithm

A simple and effective lossless data hiding algorithm is presented. Based on integer wavelet transform (IWT), a secret message is embedded in the three high subbands of IWT domain by the proposed coefficient-bias algorithm. More specifically, to provide a higher hidden space without severe distortion, only the coefficients of each block that located in a predetermined interval are utilized to hide data bits. Simulations show that not only the message is successfully extracted, but also the host images are losslessly recovered at the receiver. Besides, the hidden capability is not bad while both PSNR and perceived quality are good when a lower control parameter beta was used.