IPM Priority-Preserving Adaptive Steganography for HEVC

Video steganography in the intra prediction mode (IPM) domain embeds secret messages by modifying IPM values. However, such modifications are highly susceptible to detection by video steganalysis techniques, particularly those leveraging recompression-based calibration features. In this paper, the signal restoration phenomenon that occurs during video recompression is first modeled, which reveals the underlying reason for the effectiveness of recompression calibration-based detection features. Based on this insight, a IPM priority-preserving strategy is proposed. This strategy integrates the steganographic modification state with the optimal IPM selection mechanism during recompression, employing dynamic cost revision and joint cost decomposition to guide steganographic modifications toward optimal selection. By aligning modifications with recompression tendency, the proposed method mitigates signal restoration effects, reduces distribution discrepancies in calibration-based detection features, and enhances overall steganographic security. Extensive experimental evaluations demonstrate that the proposed scheme significantly improves resistance against both intra-frame and inter-frame steganalysis features while maintaining superior visual quality and bitrate control.