Exploiting Modification Direction Research Articles

High Capacity Data Embedding in Images by Pixel Triplets Matching

this paper a data hiding method based on pixel pair matching (PPM) is presented. Pixel pair matching uses a pair of pixel intensity values as reference coordinates and searches the coordinate neighborhood according to the given message digit. The searched coordinate which encodes the message digit is put in place of the pixel pair. Exploiting modification direction (EMD), Diamond Encoding (DE) and Adaptive Pixel Pair Matching (APPM) are recently proposed methods based on PPM. Among these Adaptive Pixel Pair Matching provides the highest capacity of embedding with a given distortion. This paper presents an extension of the method to higher dimensional coordinate system and in particular with Pixel Triplet Matching (PTM). The experiments showed that PTM achieves higher capacity while being computationally feasible. The method is also resistant to simple steganalysis with adjacent HCF-COM.

Data hiding based on generalised exploiting modification direction method

Two schemes using the exploiting modification direction (EMD) method to obtain good stego image quality and increase embedding capacity were respectfully introduced by Zhang and Wang and Lee et al. This study proposes a data-hiding scheme based on an improved EMD method. According to experimental results, the proposed scheme retains high embedding capacity and good stego image quality.

Steganography: Securing Message in wireless network

Steganography is the process of hiding a secret message with in a cover medium. However eavesdropper may guess the embedding algorithm like least significant bit (LSB) replacement of Chan et al, 2004; Wang et al, 2001; Wu et al, 2005, LSB matching of Mielikainen, 2006, addition and/or subtraction of Andead wastfield, 2001; F. Huang et al in 2011, Exploiting Modification Direction by Zhang and Wang, 2006, Binary Space Partition by Tsai and Wang, 2007, modulus function of Chin et al, 2011 and thus can apply the respective extraction method to detect the secret message. So challenges lies in the methodologies of embedding message. Capacity, security and robustness are the services to be demanded by users. Again the true-positive rate of secret message detection by eavesdropper should be lessened by applying firm technique. Thirdly operating domain should be less sensitive to the noise, margin level of losses or alteration of data while communicating through unguided medium like wireless network, sensor network and cellular network. This paper will briefly discuss the steganographic methods and their experimental results explained in the survey paper of Niels Provos and Peter Honeyman to hide and seek message. Finally the proposed results and the directions for future works are addressed.

Secure Modulus Data Hiding Scheme

In 2006, Zhang and Wang proposed a data hiding scheme based on Exploiting Modification Direction (EMD) to increase data hiding capacity. The major benefit of EMD is providing embedding capacity greater than 1 bit per pixel. Since then, many EMD-type data hiding schemes have been proposed. However, a serious disadvantage common to these approaches is that the embedded data is compromised when the embedding function is disclosed. Our proposed secure data hiding scheme remedies this disclosure shortcoming by employing an additional modulus function. The provided security analysis of our scheme demonstrates that attackers cannot get the secret information from the stegoimage even if the embedding function is made public. Furthermore, our proposed scheme also gives a simple solution to the overflow/underflow problem and maintains high embedding capacity and good stegoimage quality.

Data embedding in image-media using weight-function on modulo operations

Multimedia hiding system is to embed message behind the specified media, but it is still kept normal in media representations via human sensitive organizations without causing imperceptibility. In this article, we propose a data hiding system by means of flexible exploiting modification directions to achieve safer message concealments in image-media. In our scheme, n cover-pixels are flexibly chosen on modulo operations to embed a secret s , where n = ⌈ log 3 ( s ) ⌉. The varied pixel values associated with the chosen n pixels are only changed among [-1, 1]. Because the numbers of adjustable pixels are much greater than the pixels in the past scheme, our scheme is able to obtain a higher embedded ratio in response to the capacity requirements of information hiding systems. In addition, we also applied the statistics-steganalyzers to demonstrate that our scheme has accomplishment not only higher capacity but also kept the robustness against the blind steganalyzers.

A Steganographic Scheme Based on Formula Fully Exploiting Modification Directions

Many EMD-type data hiding schemes have been proposed. However, the data hiding capacity is less than 2bpp when the embedding procedure uses formula operations. In order to improve the data hiding capacity from 1bpp to 4.5bpp, a new data hiding scheme is proposed in this paper based on a formula using the fully exploiting modification directions method (FEMD). By using our proposed theorem, the secret data can be embedded by formula operations directly without using a lookup matrix. The simulation results and performance analysis show the proposed scheme not only maintains good embedding capacity and stegoimage quality but also solves the overflow problem. It does so without using extra memory resources and performs within a reasonable computing time. The resource usage and capabilities of this scheme are well matched to the constraints and requirements of resource-scarce mobile devices.

Invertible secret image sharing for gray level and dithered cover images

Secret image sharing approaches have been extended to obtain covers from stego images after the revealing procedure. Lin et al.’s work in 2009 uses modulus operator to decrease the share image distortion while providing recovery of original covers. Their work use gray level or binary image as cover. Stego images have approximately 43dB and 38dB PSNR for gray level and binary covers respectively. Lin et al.’s work in 2010 provides enhanced embedding capacity but does not support binary covers. Gray level covers’ PSNR is reported approximately 40dB. The proposed method enhances the visual quality of stego images regardless of intensity range of covers. Exploiting Modification Direction method is used to hide the shared values into covers. The method also utilizes modulus operator to recover original cover pixels. Stego image PSNR is approximately 47dB for gray level covers. The method provides 4–7dB increase respectively on the stego image quality compared to others. Stego images have also higher PSNR (43dB) for dithered covers. The proposed method generates stego images with higher PSNR regardless of the intensity range of the cover image.

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.

A Novel Data Embedding Method Using Adaptive Pixel Pair Matching

This paper proposes a new data-hiding method based on pixel pair matching (PPM). The basic idea of PPM is to use the values of pixel pair as a reference coordinate, and search a coordinate in the neighborhood set of this pixel pair according to a given message digit. The pixel pair is then replaced by the searched coordinate to conceal the digit. Exploiting modification direction (EMD) and diamond encoding (DE) are two data-hiding methods proposed recently based on PPM. The maximum capacity of EMD is 1.161 bpp and DE extends the payload of EMD by embedding digits in a larger notational system. The proposed method offers lower distortion than DE by providing more compact neighborhood sets and allowing embedded digits in any notational system. Compared with the optimal pixel adjustment process (OPAP) method, the proposed method always has lower distortion for various payloads. Experimental results reveal that the proposed method not only provides better performance than those of OPAP and DE, but also is secure under the detection of some well-known steganalysis techniques.

A Novel Steganographic Method with Four-Pixel Differencing and Exploiting Modification Direction

A Novel Steganographic Method with Four-Pixel Differencing and Exploiting Modification Direction

A novel multi-group exploiting modification direction method based on switch map

In this paper, we proposed a novel adjustable data hiding method. Our proposed method, which is based on exploiting modification direction (EMD) method, is called the “multi-group exploiting modification direction” method. In the multi-group method, we combine several pixel-groups to embed secret data according to the constructed switch map to simply avoid the conversion redundancy of the EMD method and the spatial redundancy of the section-wise strategy, as well as to efficiently increase the probability of achieving larger embedding capacity. According to the experimental results and mathematical justification, we verified that the multi-group method can achieve higher embedding payload and better visual quality of the image than the EMD method and section-wise strategy for simulated and real secret data.

A Secret Image Sharing Scheme with High Quality Shadows Based on Exploiting Modification Direction

Secret image sharing schemes have been developed extensively based on practicability. The schemes embed the secret image into the cover image to generate shadow images such that enough shadow images can recover the secret image and the cover image. In this paper, we employ the exploiting modification direction method to propose a new secret image sharing scheme in which the secret image and the cover image can both be recovered without distortion. The proposed scheme effectively avoids underflow and overflow, so our scheme is also suitable for binary images. In addition, the distortion of the shadow images is slight, even when the cover image is a binary image. Experimental results demonstrate that this method obtains better visual quality of shadow images than previous methods.

Anti-Forensics with Steganographic Data Embedding in Digital Images

E-forensics investigates and extracts confidential information from electronic products; in other words, the anti-forensics indicates that evidences in those products are imperceptible and undetected. This work presents an anti-forensic steganography method that can embed and extract messages from images. Highlight of exploiting modification direction (HoEMD) and adaptive EMD (AdEMD) methods use the module operation and take into account of the sensitive nature of a human visual system. The HoEMD approach exploits the pixel directions. A pixel with a larger change implies more pixel directions and, ultimately, a larger embedding capacity. The pixel differencing in the proposed AdEMD method is used to evaluate whether the pixel located in the edge area can tolerate a larger change than that of the pixel location in a smooth area. To successfully extract a message, the differencing value is maintained on the same level before and after data is concealed; a delicate adjusting phase is used as well. In contrast with the PVD and LSB replacement method of Wu et al., LSB substitution method, and Lee and Chen's data hiding scheme based on modulus function, the proposed steganography system has a larger embedding capacity and a higher image quality. Effectiveness of the proposed steganography schemes over that of a previous blind steganalyzer is demonstrated using the statistical attack of Chi-square analysis.

A steganographic scheme by fully exploiting modification directions

Recently, Zhang and Wang proposed a steganographic scheme by exploiting modification direction (EMD) to embed one secret digit d in the base-(2 × n + 1) notational system into a group of n cover pixels at a time. Therefore, the hiding capacity of the EMD method is log 2(2 × n + 1)/ n bit per pixel (bpp). In addition, its visual quality is not optimal. To overcome the drawbacks of the EMD method, we propose a novel steganographic scheme by exploiting eight modification directions to hide several secret bits into a cover pixel pair at a time. By this way, the proposed method can achieve various hiding capacities of 1, 2, 3, 4, and 4.5 bpp and good visual qualities of 52.39, 46.75, 40.83, 34.83, and 31.70 dB, respectively. The experimental results show that the proposed method outperforms three recently published works, namely Mielikainen’s, Zhang and Wang’s, and Yang et al.’s methods.

An improved section-wise exploiting modification direction method

In this paper, a novel section-wise exploiting modification direction (EMD) method is proposed. By using section-wise strategy, the proposed method combines several pixel groups of the cover image together to indicate adjusting modification directions. In each group, the data hiding is performed by the EMD method. Theoretically, we have proved that the modification directions of our section-wise approach is far from the EMD method. The experimental results show that the section-wise strategy can improve the embedding efficiency and the visual quality further than the EMD method, and reduce the possibility of detection.

Improved modification direction methods

The original exploiting modification direction (EMD) method proposed by Zhang and Wang is a novel data hiding technique which can achieve large embedding capacity with less distortion. The original EMD method can hide (2n+1)-ary numbers by modifying at most one least-significant bit (LSB) of n pixel values. The proposed methods in this paper, 2-EMD and EMD-2, modify at most two pixels of the LSB values. Efficiency of the proposed methods is shown theoretically and through experiments. The 2-EMD and EMD-2 can hide even larger numbers than the EMD with similar distortion under the same conditions. This paper shows that the EMD-2 is much better than the EMD, and slightly better than 2-EMD when n is 3, 4 and 5. The way to generate basis vector can be used for the generalization of the n-EMD and EMD-n where n>1.

A Novel Image Data Hiding Scheme with Diamond Encoding

A novel data hiding scheme in digital images with the diamond encoding by pixel value adjustment is proposed. The proposed method is the extension of the exploiting modification direction (EMD) embedding scheme. First, the process of embedding partitions the cover image into nonoverlapping blocks of two consecutive pixels and transforms the secret messages to a series of [InlineEquation not available: see fulltext.]-ary digits. For each block, the diamond encoding technique is applied to calculate the diamond characteristic value, and one secret [InlineEquation not available: see fulltext.]-ary digit is concealed into the diamond characteristic value. The diamond characteristic value is modified to secret digit and it can be obtained by adjusting pixel values in a block. This scheme is designed in such a way that the distortion of each block after diamond encoding is never out of the embedding parameter [InlineEquation not available: see fulltext.], and the block capacity is equal to [InlineEquation not available: see fulltext.]. The diamond encoding provides an easy way to produce a more perceptible result than those yielded by simple least-significant-bit substitution methods. The embedded secret data can be extracted without the original cover image. Experimental results have demonstrated that the proposed method is capable of hiding more secret data while keeping the stego-image quality degradation imperceptible.

An improvement of EMD embedding method for large payloads by pixel segmentation strategy

In this paper, a novel data hiding method by using pixel segmentation strategy is proposed. The proposed paper keeps (16 − p m ) MSBs of a pixel-pair unchanged and alters p m LSBs to indicate the virtual modifications on an m-dimensional pseudo-random vectors for carrying the secret data, where m = 2 p m - 1 - 1 . The embedding rate of proposed method is R = (log 2(2 m + 1))/2, which is greater than that of the EMD embedding method proposed by Zhang and Wang [X. Zhang, S. Wang, Efficient steganographic embedding by exploiting modification direction, IEEE Communication Letters 10 (2006) (113), pp.781–783], because the embedding rate of EMD embedding method is R = (log 2(2 n + 1))/ n, when m > 2 and n ≧ 2. The experimental results show that the proposed method increases the number of embedded secret bits more than 1.7 times compared with the EMD embedding method. Even with such high embedding capacity, the average PSNR of 44.3 dB shows that the visual quality does not decline to an unacceptable degree.