An Information Hiding Algorithm for HEVC Based on Differences of Intra Prediction Modes

Concerning the problem that the existing HEVC video data hiding algorithms have great influence on the video quality, a novel algorithm based on differences of intra prediction modes was proposed. During the process of 4 × 4 luminance prediction coding, we establish a mapping relationship between secret bits and differences of two consecutive intra predictions with directions and embed secret bits by modulating the prediction modes according to Lagrange rate distortion model. For two consecutive non-directional prediction modes, i.e. planar mode or DC mode, we embed the secret bits by modifying the prediction modes directly in order to increase the embedding capacity. The extraction of secret bits only requires decoding the intra prediction modes from the bit stream. The experimental results show that the average decrease of peak signal to noise ratio (PSNR) value was about 0.05 dB. Increment of bitrate was bounded to 1.1 %. The structural similarity (SSIM) values are all about 0.95. The experimental results indicate that the proposed algorithm has little impact on the video quality and also has considerable capacity.