Most significant bits probability arithmetic decoding for improved image steganography
高位有效位概率算术解码的图像密写改进算法

To overcome the attacking-prone drawbacks of quantization index modulation(QIM) in YASS(yet another steganographic scheme),an improved YASS algorithm based on MSBs(most significant bits)arithmetic decoding in DCT domain is proposed.First,a secret sequence is viewed as an arithmetic coding stream and recovered by arithmetic decoding with the MSBs probability of a cover signal distributed,thus the codec reset results in a same marginal distribution between decoding stream and the cover.Then,the decoded bits are reembedded as the convention.Combined with the highly random embedding of YASS,the proposed scheme has a higher security with the first order distribution historgram between the cover and the stego minimized.Experiments demonstrate that the proposed method outperforms YASS both in capability of anti-steg-analysis and the performance of coefficient distribution historgram, which is 6.8% for YASS and 6.3% for the improved one in average. It is an effective steganographic algorithm.