Improvement of stegermelc with hybrid recursive matrix encoding

This paper proposes a hybrid data representation scheme to improve the performance of a steganographic method called StegErmelc [1] in the JPEG compressed domain. Even though [1]simultaneously achieves scalable carrier capacity, high embedding efficiency, and low stego detection rate (SDR), SDR of [1] increases sharply when embedding at rate > 0.10bpc and varies severely when using different parameters. To suppress SDR and to close the performance gap when using different parameters, we propose hybrid recursive matrix encoding scheme to keep as many blocks that are operating in recursive matrix encoding mode as possible, and increase the carrier capacity precisely. Experimental results show that the proposed algorithm achieves lower SDR (stays undetected when embedding up to 0.125bpc as a result) and the performance gap is smaller when compared to [1]. Basic performance of [1] is also confirmed to be consistent regardless of the image database in use.