Reversible watermarking using enhanced local prediction

This work presents a novel histogram-based reversible data hiding scheme. Although common histogram-based reversible data hiding schemes can achieve high image quality, embedding capacity is restricted because general images usually do not contain a great number of pixels with the same pixel values. To improve embedding capacity and retain low distortion, the proposed scheme uses prediction-error values, which are derived from the difference between an original image and a predictive image, instead of using the original pixels to convey a secret message. In the proposed scheme, a predictive image is generated using the mean interpolation prediction method. Since the obtained predictive image is very similar to the original image, prediction-error values are to be tended to zero. That is, a great quantity of peak points gathers around zero. The proposed scheme takes full advantage of this property to increase embedding capacity and retain slight distortion. Moreover, a threshold is used to balance the tradeoff between embedding capacity and image quality, i.e. embedding capacity in the proposed scheme is scalable. Furthermore, only a threshold is needed to record, not a large amount of information of peak and zero points, when high embedding capacity is required. Additionally, a multilevel mechanism is employed to further increase embedding capacity. Experimental results indicate that the proposed scheme is superior to other reversible schemes in terms of both image quality and embedding capacity.

A novel image scaling based reversible watermarking scheme for secure medical image transmission

In this paper, we propose a new reversible watermarking algorithm based on additive prediction-error expansion which can recover original image after extracting the hidden data. Embedding capacity of such algorithms depend on the prediction accuracy of the predictor. We observed that the performance of a predictor based on full context prediction is preciser as compared to that of partial context prediction. In view of this observation, we propose an efficient adaptive prediction (EAP) method based on full context, that exploits local characteristics of neighboring pixels much effectively than other prediction methods reported in literature. Experimental results demonstrate that the proposed algorithm has a better embedding capacity and also gives better Peak Signal to Noise Ratio (PSNR) as compared to state-of-the-art reversible watermarking schemes.

In this paper, a new reversible data hiding scheme has been proposed using lagrange’s interpolating polynomial on interpolated sub-sampled images. First, we generate sub-sampled images from original image and enlarge its size using image interpolation. Now, we convert secret message using lagrange interpolating polynomial and generate new secret message. The new secret message is divided and stored within interleaved pixel of each interpolated sub-sampled images. At the receiver end, new secret message is extracted from interleaved pixel of each sub-sampled stego images and then lagrange’s interpolation is applied to generate original secret message. The security has been enhanced due to the distributive nature of hidden data within multiple images. The original pixels are not effected during data embedding which assure reversibility. The proposed scheme provides average embedding capacity with good visual quality measured by peak signal to noise ratio (PSNR) which is greater than 50 dB. It is observed that the proposed scheme provides better performance than other existing data hiding schemes in terms of data embedding capacity, visual quality and security. We have analyzed our stego images through RS analysis, calculate relative entropy, standard deviation and correlation coefficient of original and stego image to show the robustness under various steganographic attacks.

In this article, we propose a new lossless or reversible watermarking approach that allows the embedding of a message within categorical data of relational database. The reversibility property of our scheme is achieved by adapting the well known histogram shifting modulation. Based on this algorithm we derive a system for verifying the integrity of the database content, it means detecting addition, removal or modification of any t-uples or attributes. Such a content integrity check is independent of the manner the database is stored or structured. We illustrate the overall capability of our method and its constraints of deployment considering one medical database of inpatient hospital stay records. Especially, we reversibly watermark ICD-10 diagnostic codes.

Now high-capacity reversible watermarking has been a popular research topic in image watermarking. Existing algorithms only focus on the control of additional information, but ignore the process of original host image and watermark, so the embedding capacity is not fully utilized. In this paper, a high capacity reversible watermarking algorithm based on image segmentation and difference expansion is proposed, firstly original host image is segmented by image segmentation, secondly watermark is preprocessed using lossless compression in order to increase the number of expansible difference values and improve the compressed ability of the location map. Experiments show the proposed algorithm is better than traditional difference expansion based algorithms in respects of embedding capacity, compressed ability of location map and distortion of watermarked image.

Reversible watermarking inserts watermarks into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications where high capacity and high visual quality are major requirements for reversible watermarking. This work presents a new reversible watermarking algorithm that embeds message bits by modifying the differential histogram of adjacent pixels. To satisfy both high embedding capacity and visual quality, the proposed technique exploits the fact that the adjacent pixels are highly correlated. Also, we prevent overflow and underflow problems by designing a predicted error compensation scheme. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, higher capacity, and higher visual quality than any previous method, while maintaining low induced distortion.

Digital watermarking is a technique that embeds important data into host multimedia, such as video, image, audio, and so on, and it can be used to protect the copyright of digital cover information. One of its important techniques is reversible visible watermarking algorithm. It's not only can authenticate the reality of digital information, but also can recover the original image, and it can be used in some important special images, such as medical image, military images, and so on. In this paper, we will summarize the existing typical reversible visible watermarking algorithms, give the basic procedure of them, and analyze the performance of these algorithms.

Reversible watermarking technique can be used to protect the copyright of digital video and restore it without any distortion while extracting the watermarking information. However, for H.264/AVC streams, reversible watermarking scheme has the bottleneck for practical applications due to the intra error propagation phenomenon induced by watermark embedding. In this paper a novel decoder-based reversible watermarking algorithm with an error-drift elimination module for H.264/AVC is proposed for eliminating the error propagation, in which the watermark is embedded into some paired-coefficients of 4×4 quantized DCT block. Our experimental results have demonstrated that a good quality of watermarked video with a small increase in bit-rate while keeping high embedding capacity can be achieved in the proposed scheme.

The classical threshold control of difference expansion reversible watermarking does not ensure a fine tuning of the embedding capacity and the simple partial embedding can introduce artifacts. The newly proposed two-thresholds embedding capacity control splits the image into two parts and marks them with consecutive threshold values. Intermediate capacity values between the ones provided by the thresholds are obtained by varying the ratio between the two parts. The method ensures a fine control of the capacity without introducing artifacts. This paper proposes a lower distortion version of the two-thresholds embedding reversible watermarking scheme. Experimental results are provided.

A novel reversible image data hiding scheme based on pixel value ordering and dynamic pixel block partition

Liquid crystal displays (LCDs) have appeared in applications ranging from medical equipment to automobiles, gas pumps, laptops, and handheld portable computers. These display components present a cascaded energy attenuator to the battery of the handheld device which is responsible for about half of the energy drain at maximum display intensity. As such, the display components become the main focus of every effort for maximization of embedded system's battery lifetime. This paper proposes an approach for pixel transformation of the displayed image to increase the potential energy saving of the backlight scaling method. The proposed approach takes advantage of human visual system (HVS) characteristics and tries to minimize distortion between the perceived brightness values of the individual pixels in the original image and those of the backlight-scaled image. This is in contrast to previous backlight scaling approaches which simply match the luminance values of the individual pixels in the original and backlight-scaled images. Furthermore, this paper proposes a temporally-aware backlight scaling technique for video streams. The goal is to maximize energy saving in the display system by means of dynamic backlight dimming subject to a video distortion tolerance. The video distortion comprises of: 1) an intra-frame (spatial) distortion component due to frame-sensitive backlight scaling and transmittance function tuning and 2) an inter-frame (temporal) distortion component due to large-step backlight dimming across frames modulated by the psychophysical characteristics of the human visual system. The proposed backlight scaling technique is capable of efficiently computing the flickering effect online and subsequently using a measure of the temporal distortion to appropriately adjust the slack on the intra-frame spatial distortion, thereby, achieving a good balance between the two sources of distortion while maximizing the backlight dimming-driven energy saving in the display system and meeting an overall video quality figure of merit. The proposed dynamic backlight scaling approach is amenable to highly efficient hardware realization and has been implemented on the Apollo Testbed II. Actual current measurements demonstrate the effectiveness of proposed technique compared to the previous backlight dimming techniques, which have ignored the temporal distortion effect

This paper proposes a method to manage and utilize image and video data effectively in a smart city. Applying digital watermarking techniques, a framework for visual data security and management for smart cities is presented. In the framework, a reversible fragile or semi-fragile watermark embedded into the visual data is used to ensure trusted acquisition. Moreover, reversible metadata watermarks carrying information such as identification and other properties data is used to assist visual data management. A solution for tracing users on a large scale is presented using reversible watermarking.

Reversible watermarking is one of the main methods to authenticate and secure digital media security and revert to its original state without any losses. There are multiple reversible watermarking schemes proposed over the years. Often the proposed reversible watermarking scheme was focused on general grey-scale images. Their performance on medical images is not often evaluated. This study compares the performance of various general reversible watermarking schemes using multi-frame medical images and general grey-scale images in terms of 3 main factors, (1) computational complexity, (2) imperceptibility, and (3) embedding capacity. The result has shown that the Least Significant bits have the highest imperceptibility and embedding capacity. However, it is the least secure where outside can modify the watermarked images as long as they have the essential information.

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