Exploiting Spatiotemporal Redundancy Using Octree Decomposition to Enhance the Performance of Video Steganography

Leveraging data redundancy has long been recognized as an effective approach for concealing large amounts of secret data. In digital images, the 2D-pixel matrix inherently provides opportunities for redundancy, as each pixel is connected to its eight neighbors. Video segments, with their 3D structures, introduce an additional layer of redundancy known as temporal redundancy. Recent video steganography techniques have proposed utilizing this temporal redundancy for data concealment. This paper seeks to fully exploit the redundancy present in video segments by integrating both spatial and temporal redundancy through an Octree segmentation method. The video is divided into homogeneous, variable-sized 3D cubes to enhance redundancy in each region, thereby improving energy compaction in the 3D discrete cosine transform (3D-DCT) domain. Consequently, the hiding capacity is optimized because most of the signal’s energy is concentrated in a few significant 3D-DCT coefficients, leaving a substantial portion of insignificant coefficients. These insignificant coefficients can be replaced with secret data without significantly affecting the quality of the carrier signal.