Algorithm of High-Capacity Reversible Watermarking Based on Image Segmentation and Difference Expansion

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.

Reversible watermarking has drawn extensive attentions in recent years due to its broad applications of digital forensics and data security. This paper proposes a novel reversible watermarking approach, which has the perfect reversibility of the embedded data and the original image. In order to increase the embedding capacity, the proposed approach utilizes the enhanced local prediction to reduce the prediction error of every pixel value. Different from traditional reversible watermarking algorithms considering all the image pixels equivalently before prediction, an enhanced image is first computed by multiplying the original image with its saliency map. By linearly formulating each pixel value in an original image as a weighted sum of the enhanced pixel values in its local neighborhood, the correlation coefficients as learned weights are then solved as a least squares solution. Based on two state-of-the-art datasets, the experimental results show that the proposed approach achieves large embedding capacity with relatively low visual distortion.

This letter presents a method for digital image watermarking for copyright protection. This technique produces a watermarked image that closely retains the quality of the original host image while concurrently surviving various image processing operations such as lowpass/highpass filtering, lossy JPEG compression, and cropping. This image watermarking algorithm takes full advantage of permutation and 2-D barcode (PDF417). The actual watermark embedding in spatial domain is followed using permutated image for improving the resistance to image cropping. Much higher watermark robustness is obtainable via a simple forward error correction technique, which is the main feature of PDF417 codes. Additional features of this technique include the easy determination of the existence of the watermark and that the watermark verification procedure does not need the original host image. The experimental results demonstrate its effectiveness.

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 modern world of Internet and with the development of digital communication and multimedia application, image security has become an important concern in storage and communication. A cryptography technique provides good strength for securing and protecting images essentially in the fields as medical, law enforcement and military. Reversible watermarking provides authentication, in which original image and watermark gets recovered. In this paper, Initially, secrete image is passed through S-DES (Simple-Data Encryption Standard) using a key image, then this encrypted image is watermarked using a watermark image and a position matrix, this watermarked image is passed through RNS (Residue Number System) and finally we get our DES watermarked RNS encoded image. For decoding, we have to go in reverse order, i.e. initially reverse RNS (CRT, Chinese Remainder Theorem) followed by watermark and S-DES encoded image extraction and hence our secrete image back.

With the rapid access convenience of content brought by 5G technology, the integrity protection of content becomes more important. The reversible visible watermarking algorithm has attracted more attention due to its effective content protection. In this paper, a novel improved reversible visible image watermarking scheme based on gradient-weighted class activation mapping (Grad-CAM) and the just noticeable difference (JND) model has been presented. The proposed region of interest (ROI) selection strategy is used to locate the main protected body of images for watermark embedding. Divide the watermark and ROI into nonoverlapping blocks in the same way and then embed the classified two types of watermark blocks into corresponding ROI blocks with the JND model. The optimal bit positions for watermark embedding can be selected adaptively with JND threshold and achieve the tradeoff between the watermark visibility and watermarked image quality. For lossless image recovery and watermark extraction, the recovery information is reversibly hidden into watermarked image. In the experiments, the same process of grayscale images is used to each channel separately for color images watermarking. Besides, there are six aspects in this paper to estimate the proposed scheme; with the comparison to other reversible visible watermarking schemes, experimental results demonstrate the effectiveness of our proposed scheme.

For image authentication, the competence of accurately locating tampering and ensuring security is desirable. In this paper, a novel reversible data embedding based on Integer Wavelet Transform for tamper-proof watermarks is proposed. A contentbased watermark generated from host image is embedded into the carrier. The embedded data can be retrieved and the original host image can be recovered without distortion. The difference between the extracted watermark and the watermark generated from specific coefficients representing local features is applied to localize tampers. Experimental results show that the host image can be recovered after extracting the watermark if there are no attacks. Otherwise, the tampered positions can be localized explicitly and directly in the reconstructed host image even if the watermarked image was attacked by an invisible tampering. The proposed algorithm can be used for image authentication and tampering localization without using original image and original watermark.

Today, most of the information shared across the globe is in multimedia form like audio, video and image. With increased globalization, any type of such information can be broadcasted throughout the world easily and is accessible to multiple users for varied applications. This may lead to fraudulent claiming of data ownership which makes copyright protection a major priority in today's world. Digital Watermarking serves as a prime solution to copyright protection where we embed watermark into digital image which serves as an authenticator. In this paper, we proposed a hybrid algorithm using Image segmentation, SVD (Singular value decomposition), DWT (Discrete wavelet transformation), Homomorphic filtering and RSA encryption technique that helps to overcome various threats. Here, we proposed a new approach of digital watermarking by embedding two segmented watermarks which are obtained using two distinct threshold values on the original watermark. These threshold values are sent as secret keys to the receiver using Diffie-Hellman key exchange algorithm and can be used at the time of copyright verification. This approach of hybrid technique is being tested by applying Gaussian Noise and it gave the best results when compared with the other digital watermarking techniques.

Due to the problem that the many digital images can be modified more and more easily, watermarking algorithms are proposed. There are many types of digital watermarking algorithms, such as robust digital watermarking algorithms, watermarking schemes for authentication, and reversible digital watermarking algorithms. However, there are some special images, such as the digital medical images for remote treatment, the military images for tracking object, and the remote sensing images, and they are so sensitive to any modification that we should authenticate the copyright by special technique. And this technique is zero-bit watermarking algorithms. In this paper, about zero-bit watermarking algorithms are surveyed. The basic procedures of these classical algorithms are analyzed, and some suggestion about the zero-bit algorithms is given.

A coding layer robust reversible watermarking algorithm for digital image in multi-antenna system

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.

Digital watermarking has been widely applied to solve copyright problems of digital media relating to illegal use or distribution. In the past few years, several gray-level image watermarking algorithms have been proposed, but few of them can be applied to color image. A digital watermarking algorithm for a color watermark embedded into a color host image, based on color space transform and IWT (Integer Wavelet Transform), is proposed. According to the Human Visual System peculiarity and quantizing the wavelet coefficient, Encrypted watermark is embedded adaptively into the luminance Y of the YIQ mode in IWT domain. The proposed algorithm allows extracting the watermark without the help of the original watermark and host image. Experimental results show that the embedded watermark is invisible and robust against common image processing.

Reversible image watermarking schemes are used to protect ownership and copyrights of digital images. This paper proposes a novel reversible image watermarking scheme based on adaptive image interpolation, segmentation and additive prediction error expansion (PEE). Proposed interpolation comprises of weighted average of neighboring pixels by allocating higher and lower weights to less and more distant neighboring pixel values respectively. The proposed adaptive image interpolation focuses on detection of edges thus minimizing artifacts imposed by interpolation. The idea of embedding varying amount of watermark bits in different image segments has been explored. Simple linear iterative clustering (SLIC) based image segmentation is performed to separate very sharp, sharp, smooth and very smooth regions in image. Higher number of watermark bits are embedded in sharp regions by using additive prediction error expansion embedding technique. Simulations of proposed and existing techniques were performed on different images and compared using embedding capacity (EC), peak signal to noise ratio (PSNR), computational efficiency, image quality, mean square error (MSE), normalized cross correlation (NCC) and structural similarity index (SSIM). The experimental results show that proposed scheme achieves better results in terms of EC, PSNR, computational efficiency, image quality, MSE, NCC and SSIM as compared to existing techniques.

A blind dual color images watermarking based on singular value decomposition

A robust associative watermarking technique based on vector quantization