基于可容忍失真范围的数字图像隐写方法研究

Digital Image Steganography Based on Tolerable Error Range

以往的基于可容忍失真范围的隐写方案可以将隐写引起的失真控制在一定范围,但需要同时具备含密图像与原始图像才能提取秘密信息。提出了一种新的基于可容忍失真范围的隐写方案,该方案以一定质量因子的JPEG压缩作为可容忍失真,嵌入信息时仅在可容忍失真范围内改动原始图像,并具有含密图像的JPEG压缩版本与原始图像的JPEG压缩版本完全一致的特性,因此接收端不需原始图像,只要将含密图像与其JPEG压缩版本相减,便可提取出秘密信息,克服了原有此类方法需要原始图像才能提取秘密信息的缺点。实验结果表明,用该方案隐写所得到含密图像不仅在质量上优于其对应的JPEG压缩版本的质量,而且具有一定的抗分析安全性。

Previous proposed steganographic schemes based on tolerable error range（TER） can restrict the distortion caused by data-hiding within an accepted range, but both the stego-image and the original cover image are necessary for extracting the secret message. This paper presents a novel TER-based steganographic scheme, in which JPEG compression under a certain quality factor is regarded as TER, and the modification caused by data-hiding on each pixel is less than that caused by JPEG compression. Furthermore, the JPEG version of a stego-image is completely the same as that of the corresponding original one. At receiver side, the embedded secret data can be extracted by subtracting the stego-image from its JPEG version, so that the original cover is needless. Experimental results show that the presented scheme can gain a stego-image which is superior to its JPEG version in quality, and possesses a capability of withstanding the statistical analysis.