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 syndrome-trellis codes (STC). Experimental results demonstrate the merits of the proposed scheme in terms of undetectability and video coding performance.