Defining Embedding Distortion for Sample Adaptive Offset-Based HEVC Video Steganography

As a newly added in-loop filtering technique in High Efficiency Video Coding (HEVC), sample adaptive offset (SAO) can be utilized to embed messages for video steganography. This paper presents a novel SAO-based HEVC video steganographic scheme. The main principle is to design a suitable distortion function which expresses the embedding impacts on offsets based on minimizing embedding distortion. Two factors including the sample rate-distortion cost fluctuation and the sample statistical characteristic are considered in embedding distortion definition. Adaptive message embedding is implemented using syndrometrellis codes (STC). Experimental results demonstrate the merits of the proposed scheme in terms of undetectability and video coding performance.