Combining LSB embedding with modified Octa-PVD embedding

This paper proposes a new image steganographic method that effectively combines LSB embedding with Octa-PVD embedding. A cover image is divided into non-overlapping 3?×?3 sub-blocks, the n least significant bits of the center pixel of each sub-block is first substituted by secret data (n-LSB substitution). Then, the differences between the center pixel and its eight neighbors are calculated. For each direction, if the difference is equal or larger than a threshold (predefined by users or automatically determined by image analysis), secret data is embedded into the neighbor pixel by n-LSB substitution. Otherwise, secret data is embedded by PVD embedding, but into the neighbor pixel only. Consequently, depending on the conditions of each sub-block, a single embedding method can be used to the whole sub-block, or two embedding methods can be used alternately within a sub-block. Comparisons with existing LSB or multi-directional PVD embedding methods demonstrate that the proposed method has more optimized and higher embedding capacity and PSNR.

     

A TRIBUTE TO ALF MONGÉ

Abstract

A data hiding method using three-directional pixel-value differencing for gray images is presented in this article. The cover image is divided into non-overlapping 2 × 2 sub-blocks, and the basis pixel is selected to calculate three different values of a sub-block. Difference values are replaced by embedding the number of secret bits that are referenced by the range table. For three pixel pairs in the sub-block, the optimal pixel adjustment is preceded to reduce the distortion of visual quality. The experimental results demonstrate that the proposed method provides a high capacity and good visual quality.     

一种基于LSB的数字图像信息隐藏算法

根据载体图像和嵌入量的大小,利用随机函数确定出嵌入字节的位置,使嵌入信息分布均匀;研究了异或运算的性质,结合位平面的特点,通过位的异或运算,实现秘密信息嵌入;对嵌入的字节最多只需修改一位,可在该字节中同时嵌入两位秘密信息,提高了秘密信息嵌入量,并能无损还原.理论分析和实验结果证明了算法的有效性.     

An efficient data hiding method based on adaptive directional pixel value differencing (ADPVD)

Steganography is an important secret information communication technology in which one may send messages without others having knowledge of their existence. This paper proposes a new adaptive steganography method for color images using adaptive directional pixel-value differencing (ADPVD). The proposed method increases the capacity of the hidden secret data and improves the security of the stego-color image as well. The hiding capacity of the original PVD method is investigated by considering three directional edges: horizontal, vertical and diagonal directions using color cover image. The cover image is partitioned into 2-pixel blocks in a non-overlapping fashion and scanned in raster-scan order in all three directions. The proposed method adaptively selects the appropriate embedding directions for each color channel according to the largest embedding capacity. The security is improved since different pixel directions are employed adaptively to embed different number of message bits in each color channel. The experimental results show that the proposed method provides both larger embedding capacity and better visual quality of the stego color image compared with other PVD-based algorithms.     

An adaptive steganographic method based on the measurement of just noticeable distortion profile

This paper presents an adaptive steganographic method based on just noticeable distortion (JND) profile measurement. According to the input requirements, our method can produce a higher quality or higher embedding capacity stego-image. In the embedding secret data bits into a target pixel process, four different impact factors are utilized to compute how much information can be embedded and what the stego-pixel value will be. These are difference values that represent the correlation between neighboring pixels, the JND value of the target pixel, a predefined embedding capacity control factor, and the contents of various lengths secret data bits. The proposed method embeds more secret data bits within complex areas and less data bits in smooth areas. The difference between the target pixel and the stego-pixel values is controlled, as far as possible, to less than or equal to the JND value of the target pixel. Thus, the stego-image maintains good imperceptible property. In the extraction phase, the embedded secret data can be extracted from the stego-image without referencing the original image and the JND profile. The experimental results show that our method improves stego-image quality and conspicuously increases the embedding capacity at the same time.     

利用像素置换的自适应可逆信息隐藏

目的 像素置换作为一种可逆信息隐藏方式具有良好的抗灰度直方图隐写分析能力,但嵌入容量偏小一直是其缺陷。针对这一问题,提出了一种基于像素置换的自适应可逆信息隐藏算法。方法 首先,与传统2×2像素块结构相比构造了尺寸更小的像素对结构,使得载体图像可以被更稠密地分割,为嵌入容量的提升提供了基数条件。其次,提出适用于该新像素结构的可嵌像素对（EPP）筛选条件,避免嵌入过程引起图像质量大幅下降。之后,根据EPP的灰度趋势差异对其进行自适应预编码,提高Huffman编码压缩比,进一步提升算法嵌入容量。最终,通过像素置换嵌入信息。结果 与2×2像素块结构的非自适应图像隐写算法相比,在同样保证灰度直方图稳定性的情况下该算法的PSNR提高了32%左右,嵌入容量提高了95%以上。其中自适应性对嵌入容量提升的贡献极大。结论 本文算法同时具有抗灰度直方图隐写分析能力与高嵌入容量性的可逆信息隐藏。算法构造了更高效的可嵌单位,并且针对不同载体图像的特点对其可嵌区域进行差异化编码。实验结果表明,本文算法在具有更好的不可见性的同时,嵌入容量得到大幅提升。     

Data hiding using edge detector for scalable images

In this paper we propose a data hiding method that utilizes image interpolation and an edge detection algorithm. Image interpolation algorithm enlarges a cover image before hiding secret data in order to embed a large amount of secret data. Edge detection algorithm is applied to improve a quality of stego-image. Experimental results show that the proposed method can embed a large amount of secret data while keeping visual quality better than previous works. We demonstrate that the average capacity is 391,115bits, and the PSNR and quality index are 44.71dB, 0.9568 for gray images when threshold value is 4 and the embedding bits are given to 2 respectively.     

An Animated GIF Steganography Using Variable Block Partition Scheme

The paper presents a novel Graphics Interchange Format (GIF) Steganography system. The algorithm uses an animated (GIF) file format video to apply on, a secured and variable image partition scheme for data embedding. The secret data could be any character text, any image, an audio file, or a video file; that is converted in the form of bits. The proposed method uses a variable partition scheme structure for data embedding in the (GIF) file format video. The algorithm estimates the capacity of the cover (GIF) image frames to embed data bits. Our method built variable partition blocks in an empty frame separately and incorporate it with randomly selected (GIF) frames. This way the (GIF) frame is divided into variable block same as in the empty frame. Then algorithm embeds secret data on appropriate pixel of the (GIF) frame. Each selected partition block for data embedding, can store a different number of data bits based on block size. Intruders could never come to know exact position of the secrete data in this stego frame. All the (GIF) frames are rebuild to make animated stego (GIF) video. The performance of the proposed (GIF) algorithm has experimented and evaluated based on different input parameters, like Mean Square Error (MSE) and Peak Signal-to-Noise Ratio (PSNR) values. The results are compared with some existing methods and found that our method has promising results.     

安全的MPEG压缩视频数字隐写算法

视频数字隐写具有隐藏容量大的优点,但是通常在获得隐藏容量的间时,却忽视了安全性.为了在二者之间取得平衡,利用纠错码信息隐藏的原理,提出了一种以压缩视频为载体的数字隐写算法.该算法在进行秘密信息嵌入时,采用了二次嵌入的策略,即首先将秘密信息嵌入到纠错码码字,然后将得到的载密纠错码码字嵌入到与不采用差分编码的系数相对应的行程幅度对的幅度值,同时采用比特率控制策略来减小信息嵌入前后的视频流长度变化.实验及分析表明,该算法的隐写结果不仅具有较好的视觉和统计上的不可感知性,而且满足密码学中的"Kerchhoff准则".此外,该算法在确保一定的嵌入容量的情况下,能够使视频流长度在信息嵌入前后保持近似不变.     

An adaptive color image steganography method using adjacent pixel value differencing and LSB substitution technique

Abstract

Steganography is a data-concealing technique that provides a covert communication. This paper proposes a spatial domain color steganography method that uses a neighboring pixel-pair differencing concept to enhance the embedding capacity. The proposed method considers the distortion tolerance capacity of each color plane and the difference value between two neighboring pixels while deciding the number of bits that can be concealed in that pixel-pair. Each plane is divided into some disjoint blocks of size 3?×?3 pixels. The method forms eight pairs of pixels in one block using the eight-neighboring pixel concept, which enables the method to utilize all the edge pixels in all probable directions. It also uses the XOR encoding technique before the embedding process. This step provides an additional layer of security to the secret information. The simulation results show that the proposed method is able to achieve a high embedding capacity with good visual quality as per the calculation of imperceptibility metrics. The robustness of the method is tested by RS steganalysis and pixel difference histogram analysis. Further, a comparison between the proposed method and the existing methods on the basis of embedding capacity and stego image quality is shown.     

Using contourlet transform and cover selection for secure steganography

In this paper, we present a new adaptive contourlet-based steganography method that hides secret data in a specific or automatically selected cover image. Our proposed steganography method primarily decomposes the cover image by contourlet transform. Then, every bit of secret data is embedded by increasing or decreasing the value of one coefficient in a block of a contourlet subband. Contourlet coefficients are manipulated relative to their magnitudes to hide the secret data adaptively. In addition to proposing contourlet-based steganography method, this work investigates the effect of cover selection on steganography embedding and steganalysis results. We demonstrate, through the experiments, that choosing suitable cover image by a proper selection measure could help the steganographer reduce detectability of stego images. The proposed technique is examined with some state-of-the-art steganalysis methods, and the results illustrate that an image can successfully hide secret data with average embedding capacity of 0.02 bits per pixel in a random selected cover image. Cover selection improves the embedding capacity up to 0.06 bits per pixel. Several experiments and comparative studies are performed to show the effectiveness of the proposed technique in enhancing the security of stego images, as well as to demonstrate its gain over the previous approaches in literature.     

Data hiding by an improved exploiting modification direction

This paper represents an improved data hiding scheme, CIE, which uses a codebook to improve the Exploiting Modification Direction (EMD) embedding scheme. In our scheme, one secret (2 ^n?+?x ???1)-ary digit is hidden in a group of pixels in an image as a modified secret digit. Our proposed scheme has an embedding rate $R=\log_2(2^{n+x}-1)/n$ , which is greater than the rate of the EMD scheme, which is R?=?log₂(2n?+?1)/n for n?≥?2 . Embedding rate R is the number of secret bits embedded in each cover pixel. Our experimental results demonstrate that our scheme is able to embed 3 times as many secret bits in an image compared to the original EMD embedding scheme when n?=?2 and x?=?5. Our scheme has low time complexity and achieves this higher embedding performance while retaining reasonable perceptual quality for the image. An experiment verifies these features of our proposed data hiding scheme.     

Data hiding scheme improving embedding capacity using mixed PVD and LSB on bit plane

In data hiding, pixel-value differencing and least significant bit are well-known techniques to embed secret data. In this paper, a novel data hiding scheme is proposed to provide high embedding capacity. In case of previous methods, pixel-value differencing and least significant bit techniques were used individually or in combination based on pixel, but the proposed method utilizes first by dividing the bit region and two schemes are used simultaneously in the same bit plane. The experimental results show that the proposed method has strength on embedding capacity maintaining visual image quality without distortion to the human eyes.     

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。     

基于自适应哈夫曼编码的密文可逆信息隐藏算法

随着云存储和隐私保护的发展,密文域可逆信息隐藏作为一种可以在密文中嵌入秘密信息,保证嵌入后的信息可以无错误提取,并能无损恢复原始明文图像的技术,越来越受到人们的关注.本文提出了一种基于自适应哈夫曼编码的密文域可逆信息隐藏算法,对不同的图像采用不同的哈夫曼码字编码腾出空间来嵌入秘密信息.首先利用自然图像相邻像素间的相关性对原始明文图像进行像素值预测,从最高有效位到最低有效位,对原始像素值和预测像素值的相同比特位进行自适应的哈夫曼编码标记.然后,利用流密码对原始明文图像进行加密.最后在腾出的空间,通过位替换来自适应的嵌入秘密信息.由于哈夫曼编码和解码的可逆性,合法接收者可以对原始明文图像和秘密信息实现分离的无损恢复和提取.实验结果表明,与现有的几种方法相比,本文提出的方法具有更好的安全性和更高的嵌入率,在BOSSBase、BOWS-2和UCID三个数据集上的平均嵌入率比MPHC算法分别提高了0.09bpp、0.062 bpp和0.06bpp,在最佳情况下比MPHC算法能分别高出0.958 bpp、0.797 bpp和0.320 bpp,最差情况下的嵌入率比MPHC算法也分别高出了 0.01 bpp、0.039 bpp和0.061 bpp.     

Separable reversible data hiding in encrypted images based on scalable blocks

This paper proposes a new separable reversible data hiding method for encrypted images. Proposed scheme employs the pixel redundancy of natural images to construct embedding space. First, cover image is divided into multiple blocks with different scales. According to the pixel average value of each block, the lowest two bits of every pixel are vacated as reserved rooms. Subsequently, the whole image is encrypted by using stream cipher and the secret messages are finally embedded into the reserved rooms by the embedding key. Proposed scheme is separable in the sense that the recipient can achieve different function by the following ways: (a) If the recipient has only decryption key, an approximation plaintext image containing the embedded information can be obtained. (b) If the recipient has only embedded key, secret messages can be extracted correctly. (c) If the recipient has both decryption key and embedded key, he can not only extract the secret messages, but recover the original cover image perfectly. Extensive experiments are performed to show that our proposed schemes outperform existing reversible data hiding schemes in terms of visual quality, embedding capacity and security performance, even if a large-scale image database is used.

     

基于像素值排序与块再分的可逆数据隐藏算法

基于像素值排序的可逆数据隐藏算法通过修改图像块中的最大像素和最小像素嵌入数据,但并未充分利用图像块内的每一个像素,从而影响嵌入性能。结合块再分原理,提出基于像素值排序的可逆数据隐藏算法。将原始图像划分为3×3的图像块,计算每一个图像块的局部复杂度。设计12种分块模式将局部复杂度小于阈值的图像块细分为子块A和B。根据子块A和B的不同局部特征分别采用2种不同的扫描顺序读取像素。子块A的像素序列使用次小值预测最小值和次大值预测最大值的方法,获得2个预测误差值,子块B的像素序列利用中值像素连续预测其余4个像素的方法,得到4个预测误差值。在此基础上,利用图像块中预测误差值为0和1的像素嵌入隐藏数据。实验结果表明,该算法在一个图像块中最高可嵌入6 bit的数据,在较低计算复杂度的情况下能够有效提高像素的嵌入性能。     

基于语音参数模型的语音隐藏算法

基于语音参数模型，该文提出一种将保密语音隐藏在公开语音中的信息隐藏算法．首先将保密语音经混合激励线性预测(MELP)编码和纠错编码形成隐藏信息．然后根据瞬态互相关基音周期检测算法确定频域嵌入点，并通过修改对应的DFT系数来隐藏信息．提取时按同样方法确定嵌入点恢复隐藏信息，并经MELP解码还原保密语音．实验结果表明嵌入信息后，中间语音的分段平均信噪比接近60dB，并且在受到压缩、滤波等攻击时具有较强的鲁棒性．算法为信息安全和数字水印领域研究开辟了一条新的途径．     

Extended squared magic matrix for embedding secret information with large payload

Data hiding is a technology designed for safely transmitting secret data through open communication channels, in which the secret data are embedded into a cover carrier imperceptibly. Among the existing data hiding schemes, the exploiting-modification-direction (EMD) based schemes draw considerable attentions due to large embedding capacity. The proposed scheme improves the EMD-2 scheme by constructing an extended squared magic matrix, resulting in a larger embedding capacity high up to 3.15 bits per pixel (bpp). Experimental results show that the proposed scheme outperforms state-of-the-art reference matrix based schemes in terms of embedding capacity, meanwhile, maintains good image quality.

     

A novel data hiding for color images based on pixel value difference and modulus function

This paper proposes a novel data hiding method using pixel-value difference and modulus function for color image with the large embedding capacity(hiding 810757 bits in a 512×512 host image at least) and a high-visual-quality of the cover image. The proposed method has fully taken into account the correlation of the R, G and B plane of a color image. The amount of information embedded the R plane and the B plane determined by the difference of the corresponding pixel value between the G plane and the median of G pixel value in each pixel block. Furthermore, two sophisticated pixel value adjustment processes are provided to maintain the division consistency and to solve underflow and overflow problems. The most importance is that the secret data are completely extracted through the mathematical theoretical proof.