Embedding Regions Research Articles

English

The image fusion steganographic system embeds encrypted messages in decomposed multimedia carriers using a pseudorandom generator but it fails to evaluate the contents of the cover image. This results in the secret data being embedded in smooth regions, which leads to visible distortion that affects the imperceptibility and confidentiality. To solve this issue, as well as to improve the quality and robustness of the system, the Randomized Symmetric Crypto Spatial Fusion Steganography System is proposed in this study. It comprises three-subsystem bitwise encryption, spatial fusion, and bitwise embedding. First, bitwise encryption encrypts the message using bitwise operation to improve the confidentiality. Then, spatial fusion decomposes and evaluates the region of embedding on the basis of sharp intensity and capacity. This restricts the visibility of distortion and provides a high embedding capacity. Finally, the bitwise embedding system embeds the encrypted message through differencing the pixels in the region by 1, checking even or odd options and not equal to zero constraints. This reduces the modification rate to avoid distortion. The proposed heuristic algorithm is implemented in the blue channel, to which the human visual system is less sensitive. It was tested using standard IST natural images with steganalysis algorithms and resulted in better quality, imperceptibility, embedding capacity and invulnerability to various attacks compared to other steganographic systems.

Robust watermarking in non-ROI of medical images based on DCT-DWT.

Increasing demand and utilization of telemedicine require transmission of medical information and images over internet. Since authenticity of received images is crucial and patient's information should be included with minimum changes in images, robust watermarking schemes are needed. In this paper, we propose a robust watermark method that embeds patient's information outside the region of interest (ROI) in medical image. In order to find appropriate regions for embedding, we use saliency as a means of measuring importance of regions and find blocks having minimum overlap with the ROI. The algorithm employs wavelet transform and also discrete cosine transform (DCT) domains in the embedding stage and redundantly embeds watermark to increase robustness against possible alterations. Moreover, voting is utilized in the extraction phase. Experimental results show the efficiency of the proposed method and better results are obtained as compared to comparable methods with same size of the watermarked data.

Joint R&D Subsidies, Related Variety, and Regional Innovation

Subsidies for research and development (R&D) are an important tool of public R&D policy, which motivates extensive scientific analyses and evaluations. This article adds to this literature by arguing that the effects of R&D subsidies go beyond the extension of organizations’ monetary resources invested into R&D. It is argued that collaboration induced by subsidized joint R&D projects yield significant effects that are missed in traditional analyses. An empirical study on the level of German labor market regions substantiates this claim, showing that collaborative R&D subsidies impact regions’ innovation growth when providing access to related variety and embedding regions into central positions in cross-regional knowledge networks.

A robust watermarking framework for High Efficiency Video Coding (HEVC) – Encoded video with blind extraction process

Digital watermarking is an efficient and promising means for copyright protection of multimedia objects. Digital videos are stored and transmitted in a compressed format, which has drawn a great deal of attention in compressed domain watermarking for video. The embedding and extraction of watermark bits in compressed domain, therefore does not require complete decoding and re-encoding of the compressed video. There have been several compression standards for video. High Efficiency Video Coding (HEVC), a successor to H.264 Advanced Video Coding (AVC), is the latest standard for video compression with high compression efficiency. In this paper, we propose a robust watermarking framework with a blind extraction process for HEVC encoded video. A readable watermark is embedded invisibly in 4×4 intra predicted blocks of the HEVC encoded video. Our watermarking framework enforces security by exploring the spatio-temporal characteristics of the compressed video and a random key for selection of embedding regions. We also analyze the strengths of different compressed domain features of HEVC encoded video for implementing the embedding algorithm. Experimental results demonstrate that the proposed work restrict the increase in video bit rate and degradation of perceptual quality. The proposed framework can also survive filtering, compressions, and noise additions maintaining good quality and robustness.

PDE based scheme for multi-modal medical image watermarking.

BackgroundThis work deals with copyright protection of digital images, an issue that needs protection of intellectual property rights. It is an important issue with a large number of medical images interchanged on the Internet every day. So, it is a challenging task to ensure the integrity of received images as well as authenticity. Digital watermarking techniques have been proposed as valid solution for this problem.MethodsIt is worth mentioning that the Region Of Interest (ROI)/Region Of Non Interest (RONI) selection can be seen as a significant limitation from which suffers most of ROI/RONI based watermarking schemes and that in turn affects and limit their applicability in an effective way. Generally, the ROI/RONI is defined by a radiologist or a computer-aided selection tool. And thus, this will not be efficient for an institute or health care system, where one has to process a large number of images. Therefore, developing an automatic ROI/RONI selection is a challenge task. The major aim of this work is to develop an automatic selection algorithm of embedding region based on the so called Partial Differential Equation (PDE) method. Thus avoiding ROI/RONI selection problems including: (1) computational overhead, (2) time consuming, and (3) modality dependent selection.ResultsThe algorithm is evaluated in terms of imperceptibility, robustness, tamper localization and recovery using MRI, Ultrasound, CT and X-ray grey scale medical images. From experimental results that we have conducted on a database of 100 medical images of four modalities, it can be inferred that our method can achieve high imperceptibility, while showing good robustness against attacks. Furthermore, the experiment results confirm the effectiveness of the proposed algorithm in detecting and recovering the various types of tampering. The highest PSNR value reached over the 100 images is 94,746 dB, while the lowest PSNR value is 60,1272 dB, which demonstrates the higher imperceptibility nature of the proposed method. Moreover, the Normalized Correlation (NC) between the original watermark and the corresponding extracted watermark for 100 images is computed. We get a NC value greater than or equal to 0.998. This indicates that the extracted watermark is very similar to the original watermark for all modalities.ConclusionThe key features of our proposed method are to (1) increase the robustness of the watermark against attacks; (2) provide more transparency to the embedded watermark. (3) provide more authenticity and integrity protection of the content of medical images. (4) provide minimum ROI/RONI selection complexity.

A Real Time Visible Watermarking Technique using Dual Tree Complex Wavelet Transformation

The key idea of this paper is to propose a real-time, selfauthenticating, watermarking technique. Here the watermark has been constructed from the image itself using Toeplitz matrix and the embedding region is selected by the user at real-time. Embedding region should be selected from Region of Non Interest (RONI) of the image. Dual Tree Complex Wavelet transformations (DT-CWT) based embedding technique has been applied for the embedding purpose. The key is shared or transferred to the receiver through a secret channel. At the receiving end, the extracted watermark is matched with the matrix generated from the bit-sequence (key) which ensures the originality of the image.

Image Watermarking Scheme Based on Geometric Invariant Features

Digital watermarking technology resistant against geometric attacks can enhance the robustness of the watermarking scheme, and protect the copyright of the digital media efficiently. In this paper, we mainly research the digital watermarking algorithm based on image geometric invariant feature. Harris corner detection algorithm was exploited to extract the feature points and determine the most stable local point through the response value. These local points were made to generate a circular region. The resulting region is the watermark embedding and extraction region. And DCT and IDCT were used to embed and extract the watermark. The experimental results show that we can embed and extract the watermark accurately by using Harris algorithm for image content feature point and the proposed scheme has a good feasibility and correctness.

A Visual Hiding Algorithm Based on Human Visual System

Image information hiding is a way of concealing secret information within another image or file. The previous researches of image information hiding extract secret by calculating. An algorithm based on HVS (Human Visual System) is proposed in this paper. We first decide the embedding region and embedding strength of secret image based on edge and texture information. Then, a pair of invert images is chosen as the cover images, and the stego images are constructed by modifying the pixels of the cover images through the proposed criterion. Correspondingly, the secret image can be recovered through overlaying the two stego images.

Chaos-based Spatial Steganography System for Images

In this paper, we propose a chaos-based enhancement of two spatial steganographic algorithms; the AE-LSB and the EA-LSBMR and our objective is to study their performances. The first algorithm is an adaptive LSB (Least Significant Bit) steganographic method using pixel value difference that provides a large embedding capacity and imperceptible stego images. The second method is an edge adaptive scheme which can select the embedding region according to the size of secret message and the difference between two adjacent pixels in the cover image. The two methods suffer from low security against attacks that try to recover secret data.To overcome this weakness, we propose to enhance the message security of these methods. The enhancement consists of using an efficient chaotic system in order to choose in a pseudo-chaotic manner the pixels in the cover image where the bits of the secret message will be embedded. In this way, the inserted message becomes secure against message recovery attacks and becomes as well spread over the whole image in a uniform manner. Experiments show that the security of the algorithms is increased.

Histogram modification based image watermarking resistant to geometric distortions

A geometrically invariant digital image watermarking scheme based on histogram modification is proposed in this paper. The feature extraction method called Adaptive Harris Detector with Simulated Attacks is proposed and employed, which adjusts and ranks the response threshold value of the traditional Harris Corner Detector, and trains the input image with several simulated attacks, to extract the most reliable feature points for watermark data bits embedding and extraction. The watermark embedding regions are then found as square patches centering at the selected geometric invariant feature points. In each region, the intensity-level histogram is modified by moving some pixels to form a specific pattern according to the corresponding watermark bit. For watermark extraction, the proposed Adaptive Harris Detector with Simulated Attacks is proposed to restore the watermarked image to its original position if any geometric attack exists, and to retrieve the watermarked regions. According to the pattern of intensity-level histogram distribution in these regions, a sequence of watermark bits is then extracted. Experimental results show that the proposed scheme is robust against both the geometric attacks and common signal processing, such as rotation, scaling, cropping, JPEG compression, median filtering, low-pass Gaussian filtering and also noise pollution.

Sensing membrane stresses by protein insertions.

Protein domains shallowly inserting into the membrane matrix are ubiquitous in peripheral membrane proteins involved in various processes of intracellular membrane shaping and remodeling. It has been suggested that these domains sense membrane curvature through their preferable binding to strongly curved membranes, the binding mechanism being mediated by lipid packing defects. Here we make an alternative statement that shallow protein insertions are universal sensors of the intra-membrane stresses existing in the region of the insertion embedding rather than sensors of the curvature per se. We substantiate this proposal computationally by considering different independent ways of the membrane stress generation among which some include changes of the membrane curvature whereas others do not alter the membrane shape. Our computations show that the membrane-binding coefficient of shallow protein insertions is determined by the resultant stress independently of the way this stress has been produced. By contrast, consideration of the correlation between the insertion binding and the membrane curvature demonstrates that the binding coefficient either increases or decreases with curvature depending on the factors leading to the curvature generation. To validate our computational model, we treat quantitatively the experimental results on membrane binding by ALPS1 and ALPS2 motifs of ArfGAP1.

Reversible data hiding using Delaunay triangulation and selective embedment

In this paper, we propose a reversible data hiding method based on prediction and histogram-shifting (PHS) using Delaunay triangulation and selective embedment. Because the statistical properties of the prediction errors along the embedding direction are significantly altered due to the shifting operation, the existing PHS-based methods are vulnerable to some steganalyzers. The proposed method exploits a set of key-selected referential pixels to construct a 3D Delaunay mesh to obtain the prediction errors. The presence of the altered statistical properties along the embedding direction is unrevealed because the same set of prediction errors cannot be reconstructed. A selective embedment mechanism is used to control the embedding regions in the cover image for evading the detection of the steganalyzers based on low-amplitude stego signal. The experimental results reveal that the proposed method not only provides better payload and image quality than the existing PHS-based methods, but is also robust to the detection of modern steganalyzers such as histogram analysis and SPAM.

Video Steganography Using LSB Matching Revisited Algorithm

Video Steganography deals with hiding secret data or information within a video. In this paper, a spatial domain technique for LSB Matching Revisited algorithm (LSBMR) has been proposed, where the secret information is embedded in the cover frames. LSB Matching Revisited(LSBMR) algorithm selects the embedding regions according to the size of secret message and the difference between two consecutive pixels in the cover image. For embedding rates is lower , only sharper edge regions are used while keeping the other smoother regions as they are. In the proposed approach, LSB Matching Revisited algorithm is used to embed the secret message into the video. Hence large amounts of data can be embedded and also preserving higher visual quality of stego images at the same time.The proposed method is analyzed in terms of both Peak Signal to Noise Ratio (PSNR) compared to the original cover video as well as the Mean Squared Error (MSE) measured between the original and steganographic files averaged over all video frames.

Genetic algorithms based data hiding scheme for digital images with LSBMR

Modern information hiding technology plays a vital role in information security. Steganography is the art and science of scripting hidden messages in such a manner that no one, except the sender and directed receiver realise the existence of the message. Image steganography is the most well-liked method for message cover up. In LSBMR, two covert bits is fixed into each embedding unit and the threshold value for region selection is determined. The major disadvantage of this scheme is the total difference is taken as the threshold value. In this paper, LSB matching revisited LSBMR image steganography using genetic algorithm GA is proposed, in which genetic algorithm is used to select the embedding regions according to the size of the secret message and to optimise the threshold value of the selected image regions. Experimental analysis shows that the proposed algorithm outperforms the existing methods in terms of capacity and security.

An improved reversible data hiding-based approach for intra-frame error concealment in H.264/AVC

As H.264/AVC video streams are highly compressed, they become sensitive to errors caused by unreliable transmission channels. In order to address this issue, an improved version of Chung et al.’s reversible data hiding-based approach for intra-frame error concealment is proposed for H.264/AVC codec. By using the histogram shifting technique, the original work reversibly embeds the motion vector (MV) of a macroblock (MB) into other MB within the same intra-frame. If an MB is corrupted at the decoder side, the embedded MV can be extracted from the corresponding MB for the recovery of the corrupted MB. However, Chung et al.’s work did not fully exploit the number of coefficients which need to be modified in order to reversibly hiding data, and did not consider many extra nonzero residual blocks produced by data hiding. These two issues could reduce the visual quality of the stego-video. This paper adopts MV data pre-processing, the selection of most suitable embedding region, and the minimum possible amount of histogram modification, which lead to higher PSNR of the stego-video for a given payload. Experimental results further reveal that the proposed method offers stego-video with better visual quality over Chung et al.’s work.

Geometrically Resilient Digital Image Watermarking by Using Interest Point Extraction and Extended Pilot Signals

A feature-based digital image watermarking scheme is proposed to resist geometrical transformations. Such interest point extraction as scale-invariant feature transform is applied to form the invariant regions for signal embedding. Along with the watermark, the pilot signal used for synchronized detection will also be embedded to help to determine larger areas for improving the payload of watermarking and/or increasing the confidence of watermark detection. Both embedded signals are weighted by the just noticeable difference of Watson's perceptual model to meet the requirement of invisibility. In the detection phase, after the same interest point extraction, synchronization can be achieved via adjusting the related affine parameters of grids on the investigated image to detect the possible hidden pilot signal so that the watermark can be successfully retrieved afterward. Experimental results show the feasibility of the proposed method.

Secret information sharing algorithm based on CL multi-wavelet and combination bit plane for confidential communication

In view of the contradiction between capability, invisibility and robustness of the existing information hiding algorithms, a preprocessing algorithm for digital image based on CL( Chui-Lian) multi-wavelet transform and Combination Bit Plane( CBP) was proposed. Then the digital image preprocessed by CL multi-wavelet and CBP was taken as the cover image to embed secret information for confidential communication and image sharing. CL multi-wavelet transform could divide the cover image into four lowest resolution sub-images with different energy level. And CBP method could analyze the above four subimages into different bit planes as the final embedding regions. During the hiding procedure, robust information, secret information and fragile information could be embedded according to the energy and robustness characteristics of the embedding regions. The experimental results show that the robustness against several common attacks described in this paper has certain enhancement compared with other two methods when the embedding rate is 25%. The Peak Signal-to-Noise Ratio( PSNR) is increased by 37. 16% and 20. 00% respectively compared with Discrete Cosine Transform-Least Significant Bit( DCT-LSB)and Discrete Wavelet Transform-Least Significant Bit( DWT-LSB) algorithm.

Adaptive image steganography using contourlet transform

This work presents adaptive image steganography methods which locate suitable regions for embedding by contourlet transform, while embedded message bits are carried in discrete cosine transform coefficients. The first proposed method utilizes contourlet transform coefficients to select contour regions of the image. In the embedding procedure, some of the contourlet transform coefficients may change which may cause errors at the message extraction phase. We propose a novel iterative procedure to resolve such problems. In addition, we have proposed an improved version of the first method in which it uses an advanced embedding operation to boost its security. Experimental results show that the proposed base method is an imperceptible image steganography method with zero retrieval error rate. Comparisons with other steganography methods which utilize contourlet transform show that our proposed method is able to retrieve all messages perfectly, whereas the others fail. Moreover, the proposed method outperforms the ContSteg method in terms of PSNR and the higher-order statistics steganalysis method. Experimental evaluations of our methods with the well known DCT-based steganography algorithms have demonstrated that our improved method has superior performance in terms of PSNR and SSIM, and is more secure against the steganalysis attack.

A Joint FED Watermarking System Using Spatial Fusion for Verifying the Security Issues of Teleradiology

Teleradiology allows transmission of medical images for clinical data interpretation to provide improved e-health care access, delivery, and standards. The remote transmission raises various ethical and legal issues like image retention, fraud, privacy, malpractice liability, etc. A joint FED watermarking system means a joint fingerprint/encryption/dual watermarking system is proposed for addressing these issues. The system combines a region based substitution dual watermarking algorithm using spatial fusion, stream cipher algorithm using symmetric key, and fingerprint verification algorithm using invariants. This paper aims to give access to the outcomes of medical images with confidentiality, availability, integrity, and its origin. The watermarking, encryption, and fingerprint enrollment are conducted jointly in protection stage such that the extraction, decryption, and verification can be applied independently. The dual watermarking system, introducing two different embedding schemes, one used for patient data and other for fingerprint features, reduces the difficulty in maintenance of multiple documents like authentication data, personnel and diagnosis data, and medical images. The spatial fusion algorithm, which determines the region of embedding using threshold from the image to embed the encrypted patient data, follows the exact rules of fusion resulting in better quality than other fusion techniques. The four step stream cipher algorithm using symmetric key for encrypting the patient data with fingerprint verification system using algebraic invariants improves the robustness of the medical information. The experiment result of proposed scheme is evaluated for security and quality analysis in DICOM medical images resulted well in terms of attacks, quality index, and imperceptibility.

A Confidential Communication-Oriented Information Hiding Algorithm based on GHM multi-wavelet and DCT

Structure and energy properties of carrier are considered as the most important factors to information hiding performance. This paper develops a new method to analyze energy and structure characteristics of digital images in order to preprocess the carriers. We adopt GHM multi-wavelet transformation to decompose the cover image into sub-images with different energy level. Then we obtain the embedding regions which are expressed as numerical range by discrete cosine transform. We embed data with different robustness in different regions. Then we get the stego image which is rarely changed in energy and structure properties compared with the original cover image. Experimental results indicate that the invisibility and robustness can be increased separately by 26.87% and 19.25% averagely, and the ability against steganalysis such as RS and Higher Order Statistics based on wavelet coefficients can be improved. Moreover, our algorithm has excellent sensitivity of image processing.