基于直方图对的JPEG图像无损数据隐藏

提出一种基于直方图对的JPEG图像无损数据隐藏方法。该方法通过调整直方图,在JPEG图像的量化后DCT中频系数中嵌入隐藏数据。同时,能够在不需要原始图像的情况下对隐藏数据进行盲提取并无损恢复图像数据。通过设置2个阈值来选择调整的直方图对和进行调整的DCT系数块,该方法能够在嵌入大数据量的同时依然保持较好的视觉效果。     

基于直方图对的MPEG-4格式视频无损数据隐藏

针对视频中的无损数据隐藏问题,提出了基于直方图对数据嵌入的方法,在I帧的离散余弦变换(DCT)域中,通过选择合理的起伏值、频段和区域来进行数据嵌入,达到了MPEG-4视频高质量的嵌入效果。通过选择在图像空域的最优局部区域的宏块(8×8),在DCT宏块内部最优频率范围内,在最优DCT幅度上嵌入数据,来达到视频的最优直方图对无损嵌入。在6个常用的测试视频序列的实验中,得到比过去方法更高的峰值信噪比（PSNR）。如akiyo视频,I帧嵌入PSNR,分别达到了45.33dB（1000b/帧）、43.58dB（2000b/帧）和40.28dB（4000b/帧）。在大嵌入量的情况下,依旧保持了较低的比特率的增加,平均约6%。在DCT系数上嵌入数据,所提算法比“基于DCT量化表”上嵌入数据得到的PSNR更高。嵌入I帧比嵌入B帧好,形成了比较完备的视频无损数据隐藏方法。     

结合层次结构和直方图平移的无损数据隐藏

针对现有基于差值直方图方法利用原始图像结构关系上的不足,提出了一种基于层次结构和差值直方图平移的无损数据隐藏方法RDH-HSDHS。RDH-HSDHS利用原始图像数据块中像素的差值形成直方图,充分利用图像中相邻像素间的相关性嵌入数据,为了进一步利用数据块中的参考像素进行数据嵌入,将参考像素组成新的图像进行下一层水印嵌入,直到当前层的嵌入容量小于解码所需的附加信息的长度或隐秘图像质量小于给定阈值。实验仿真结果表明,RDH-HSDHS能较好利用原始图像的全局和局部特性,在嵌入容量和隐秘图像质量之间达到较好的折中,在隐秘图像质量超过30 dB的同时,嵌入容量大于0.75 bit/pixel。另外,与相似方法的性能比较证明了提出方法的优势。该方法能有效应用于高质量需求的图像载体中进行信息隐藏。     

压缩差值后的双直方图平移可逆信息隐藏方法

基于直方图平移(Histogram Shifting, HS)的可逆信息隐藏(Reversible Data Hiding, RDH)是目前信息隐藏中最为普遍的技术,特别是对于结合了差值扩展和直方图平移的方法来说,可以实现较高的嵌入容量和较低的图像失真。文中提出了一种压缩差值后的双直方图平移的可逆信息隐藏方法。该算法通过综合压缩、差值及优化后的直方图平移这3种方法,改进了现有基于直方图平移方法嵌入容量不够大的缺陷,同时也给出了图像像素值在平移过程中产生溢出的处理方式。在接收端,不仅能够完整地提取数据,也能够进行无损的图像恢复。将所提方法与当前流行的4种方法进行了比较,所提方法在嵌入容量方面优于现有的基于直方图平移的算法,其嵌入容量与近年的4种方法相比提升了23%,11%,57%和93%。实验结果表明,所提方法的嵌入容量大幅增加,能够有效地实现大嵌入容量的可逆信息隐藏。     

基于预测熵的JPEG图像无损数据隐藏

针对数据隐藏中的子块选择问题,提出一种基于预测熵的JPEG图像无损数据隐藏方法。利用直方图对法预测JPEG图像DCT系数块的熵,选择熵小的子块,并在中低频系数中嵌入数据。该方法可实现嵌入数据的盲提取和图像数据的无损恢复,且无需记录嵌入数据的子块位置。实验结果表明,与其他方法相比,该方法获得图像的峰值信噪比较高,数据隐藏性能较好。     

基于整数小波最优直方图对的图像无损数据隐藏

嵌入位置图法是目前国内外普遍应用的图像数据隐藏方法,但其嵌入量不够大,图像的视觉效果也一般。针对此不足,提出一种基于多灰度图像真实性认证的直方图对无损数据隐藏新方法。该方法对灰度图像进行整数小波变换(IWT),并在直方图上选取最优阈值,通过构造直方图对进行数据嵌入。实验表明,在嵌入容量为0.1bpp时,峰值信噪比达到46dB,嵌入效果较好。     

基于块参照像素的无损信息隐藏算法

提出一种具有高嵌入容量的图像无损信息隐藏算法。首先将载体图像分成互不重叠的子块,然后在每块中选定一个参照像素,并计算参照像素与块内其它像素的差。在像素差直方图移位产生冗余空间之后,机密信息就可以无损地嵌入到这些冗余空间中。该方法在机密信息提取后可完全恢复载体图像,而且提取机密信息和恢复载体图像不需要除机密信息长度之外的任何信息。实验结果表明了该算法的有效性。     

基于整数小波阈值嵌入的无损数据隐藏

提出了基于整数小波阈值嵌入的无损数据隐藏方法。在图像的小波子带系数的最低位（LSB）嵌入隐藏数据,将数据嵌入到小波CDF(2,2)的高频子带系数中,符合人的视觉系统原理(HVS)。并使用直方图调整的方法防止溢出。小波阈值嵌入利用阈值T控制小波系数在最低位是否插入隐藏数据。该方法嵌入数据容量大(相同PSNR),PNSR高(相同容量）。通过对CorelDraw图像库1096幅图像测试,证明了提出的方法是有效的。     

基于直方图技术的无损数据隐藏

提出一种无损图像数据隐藏的方法。该方法基于无损数据隐藏的基本原理,选择灰度图像作为载体及要隐藏的数据,采用直方图调整技术来防止灰度图像边界数据值的溢出,用整数小波的提升变换及直方图峰值点移动形成空位的方法完成数据的嵌入。实验结果表明该算法不仅嵌入信息量大,而且失真小易重构,被广泛应用于医学、法律、军事等领域。     

基于图像块像素差的大容量无损信息隐藏算法

为使提取嵌入的秘密信息后能无损恢复原始载体图像,提出一种基于图像块相邻像素差的大容量无损信息隐藏算法。将原始载体图像进行分块,并按一定顺序扫描图像块得到一系列像素序列,通过计算每个序列中相邻像素的差值得到差值直方图,从中选择2个最大峰值点将秘密信息嵌入。实验结果表明,与其他无损嵌入算法相比,该算法在保证较好不可见性的情况下,信息嵌入容量较大,峰值信噪比较高。     

Issues and solution on distortion drift in reversible video data hiding

Different from reversible image data hiding, most reversible video data hiding schemes have the particular problem that the distortion due to hidden data will spread and accumulate. In this paper, the problem of distortion drift caused by reversible data hiding in compressed video is analyzed, and a lossless drift compensation scheme is proposed to restrain the distortion for the first time. In order to ensure the reversibility, drift compensation signals are merged in the quantized DCT (Discrete Cosine Transform) coefficients of P-frames and the corresponding recovery mechanism is presented as well. Experimental results demonstrate that the proposed lossless drift compensation scheme significantly improves the video quality, and the original compressed video can be recovered exactly after the hidden data and compensation signals are removed. In addition, the proposed scheme does not depend on specific reversible data hiding method.     

Adaptive lossless steganographic scheme with centralized difference expansion

In this paper, a novel adaptive lossless data hiding scheme is presented that is capable of offering greater embedding capacity than the existing schemes. Unlike the fixed hiding capacity each block provides in most of the currently available lossless data hiding approaches, the proposed method utilizes a block-based lossless data embedding algorithm where the quantity of the hidden information each block bears is variable. To both reduce the image distortion and increase the hiding capacity, the payload of each block depends on its cover image complexity. Due to the fact that schemes with difference expansion tend to damage the image quality seriously in the edge areas, in the proposed scheme, smoother areas are chosen to conceal more secret bits. This way, a better balance can be reached between the embedding ratio and the stego-image quality. In addition, when recovered the cover image can came back to its old self to the last bit without any distortion at all. Experimental results, as this paper will show, have demonstrated that the proposed method is capable of hiding more secret data while maintaining imperceptible stego-image quality degradation.     

统计量移位的鲁棒无损图像信息隐藏

鲁棒无损信息隐藏在医学成像、法律取证、遥感等领域有广泛的应用。提出了一种鲁棒无损图像信息隐藏算法。在含密载体图像未受损情况下,正确提取秘密信息后可无损恢复原始载体图像;在含密载体图像受到一定程度JPEG2000压缩攻击后,秘密信息仍然可以被正确提取。首先将原始载体图像分块并计算每个图像块的统计量,再根据统计量绝对值的最大值选择合适的阈值对统计量进行移位,最后利用移位后的统计量来嵌入秘密信息。实验结果表明,该算法在图像视觉质量、嵌入容量和鲁棒性3个方面都具有很好的性能。与其他鲁棒无损嵌入方法相比,在图像视觉质量和鲁棒性大致相当的情况下,该算法的嵌入容量有了很大提高,表明该算法较其他算法具有明显的优势。     

A lossless robust data hiding scheme

This paper presents a lossless robust data hiding scheme. The original cover image can be recovered without any distortion after the hidden data have been extracted if the stego-image remains intact, and on the other hand, the hidden data can still be extracted correctly if the stego-image goes through JPEG compression to some extent. The proposed scheme divides a cover image into a number of non-overlapping blocks and calculates the arithmetic difference of each block. Bits are embedded into blocks by shifting the arithmetic difference values. The shift quantity and shifting rule are fixed for all blocks, and reversibility is achieved. Furthermore, owing to the separation of bit-0-zone and bit-1-zone as well as the particularity of arithmetic difference, minor alteration applying to the stego-image generated by non-malicious attacks such as JPEG compression will not cause the bit-0-zone and the bit-1-zone to overlap, and robustness is achieved. Experimental results show that, compared with previous works, the performance of the proposed scheme is significantly improved.     

利用改进整数变换实现图像无损信息隐藏

为了在图像中实现无损信息隐藏,并提高数据嵌入容量和隐蔽性,给出一种基于改进整数变换的无损信息隐藏方法。首先对图像块采用改进算法进行整数变换,使得变换前后图像块引入失真较少,然后自适应选择整数变换后引入失真较小的可修改图像块进行整数变换,并嵌入较大数据量的机密信息,在公共信道进行传输后接收端能正确提取机密信息,并无损恢复原宿主图像。实验结果表明,该方法具有较大的数据嵌入容量和较好的隐蔽性,可用于医学图像中隐藏病历信息及遥感、军事图像的无损隐秘传输等领域。     

Reversibility of image with balanced fidelity and capacity upon pixels differencing expansion

Reversible data hiding has attracted considerable attention in recent years. Being reversible, the decoder can extract hidden data and recover the original image completely, and the difference expansion (DE) scheme can lead to a lossless pixel after secret data exacting. Furthermore, despite achieving pixel reversibility based on the concept of expanded differencing, the difference expansion scheme can cause enormous image distortion because of the size of the difference. The proposed scheme in this paper describes a novel prediction for achieving predictive error based reversible data hiding by considering the relation between a pixel and its neighboring pixel and using the predictor to identify the projected difference in pixel value. Experimental results show that the proposed scheme is capable of providing great embedding capacity without causing noticeable distortion by selecting the minimal predictor based on pixel expansion. In multilevel cases, this proposed method performs better than other existing methods. Moreover, the proposed scheme is able to pass the Chi-square test, a test used to find whether an image utilizes LSB for data hiding.     

A high capacity reversible data hiding scheme with edge prediction and difference expansion

To enhance the embedding capacity of a reversible data hiding system, in this paper, a novel multiple-base lossless scheme based on JPEG-LS pixel value prediction and reversible difference expansion will be presented. The proposed scheme employs a pixel value prediction mechanism to decrease the distortion caused by the hiding of the secret data. In general, the prediction error value tends to be much smaller in smooth areas than in edge areas, and more secret data embedded in smooth areas still meets better stego-image quality. The multiple-base notational system, on the other hand, is applied to increase the payload of the image. With the system, the payload of each pixel, determined by the complexity of its neighboring pixels, can be very different. In addition, the cover image processed by the proposed scheme can be fully recovered without any distortion. Experimental results, as shown in this paper, have demonstrated that the proposed method is capable of hiding more secret data while keeping the stego-image quality degradation imperceptible.     

Prediction-based reversible data hiding

For some applications such as satellite and medical images, reversible data hiding is the best solution to provide copyright protection or authentication. Being reversible, the decoder can extract the hidden data and recover the original image without distortion. In this paper, a reversible data hiding scheme based on prediction error expansion is proposed. The predictive value is computed by using various predictors. The secret data is embedded in the cover image by exploiting the expansion of the difference between a pixel and its predictive value. Experimental results show that our method is capable of providing a great embedding capacity without making noticeable distortion. In addition, the proposed scheme is also applicable to various predictors.