http://romisatriawahono.net/lecture/rm/survey/computer%20vision/Subhedar%20-%20Image%20Steganography%20-%202014.pdf

Current status and key issues in image steganography

The illegal distribution of a digital movie is a common and significant threat to the film industry. With the advent of high-speed broadband Internet access, a pirated copy of a digital video can now be easily distributed to a global audience. A possible means of limiting this type of digital theft is digital video watermarking whereby additional information, called a watermark, is embedded in the host video. This watermark can be extracted at the decoder and used to determine whether the video content is watermarked. This paper presents a review of the digital video watermarking techniques in which their applications, challenges, and important properties are discussed, and categorizes them based on the domain in which they embed the watermark. It then provides an overview of a few emerging innovative solutions using watermarks. Protecting a 3D video by watermarking is an emerging area of research. The relevant 3D video watermarking techniques in the literature are classified based on the image-based representations of a 3D video in stereoscopic, depth-image-based rendering, and multi-view video watermarking. We discuss each technique, and then present a survey of the literature. Finally, we provide a summary of this paper and propose some future research directions.

An Overview of Digital Video Watermarking

We report on progress in algorithms for iterative phase retrieval. The theory of convex optimization is used to develop and to gain insight into counterparts for the nonconvex problem of phase retrieval. We propose a relaxation of averaged alternating reflectors and determine the fixed point set of the related operator in the convex case. A numerical study supports our theoretical observations and demonstrates the effectiveness of the algorithm compared to the current state of the art.

/pdf/relaxed-averaged-alternating-reflections-for-diffraction-2jxe6zi8wu.pdf

Relaxed averaged alternating reflections for diffraction imaging

A robust blind color image watermarking in quaternion Fourier transform domain

This work proposes a novel dual-channel time-spread echo method for audio watermarking, aiming to improve robustness and perceptual quality. At the embedding stage, the host audio signal is divided into two subsignals, which are considered to be signals obtained from two virtual audio channels. The watermarks are implanted into the two subsignals simultaneously. Then the subsignals embedded with watermarks are combined to form the watermarked signal. At the decoding stage, the watermarked signal is split up into two watermarked subsignals. The similarity of the cepstra corresponding to the watermarked subsignals is exploited to extract the embedded watermarks. Moreover, if a properly designed colored pseudonoise sequence is used, the large peaks of its auto-correlation function can be utilized to further enhance the performance of watermark extraction. Compared with the existing time-spread echo-based schemes, the proposed method is more robust to attacks and has higher imperceptibility. The effectiveness of our method is demonstrated by simulation results.

A Dual-Channel Time-Spread Echo Method for Audio Watermarking

The increasing popularity of the internet means that digital multimedia are transmitted more rapidly and easily. And people are very aware for media ownership. However, digital watermarking is an efficient and promising means to protect intellectual properties. Based on the intellectual property attention in the information era, how to protect the personal ownership is extremely important and a necessary scheme. In this paper, we propose an effective video watermarking method based on a pseudo-3-D discrete cosine transform (DCT) and quantization index modulation (QIM) against several attacks. The watermark is mainly inserted into the uncompressed domain by adjusting the correlation between DCT coefficients of the selected blocks, and the watermark extraction is blind. This approach consists of a pseudo-3-D DCT, watermark embedding, and extraction. A pseudo-3-D DCT, which is taken DCT transformation twice, will be first utilized to calculate the embedding factor and to obtain the useful messages. Using the QIM, we embed the watermark into the quantization regions from the successive raw frames in the uncompressed domain and record the relative information to create a secret embedding key. This secret embedding key will further apply to extraction. Experimental results demonstrate that the proposed method can survive filtering, compressions, luminance change, and noise attacks with a good invisibility and robustness.

A Video Watermarking Technique Based on Pseudo-3-D DCT and Quantization Index Modulation

The increasing popularity of the internet suggests that digital multimedia has become easier to transmit and acquire more rapidly. This also means that this multimedia has become more susceptible to tampering through forgery. One type of forgery, known as copy-move duplication, is a specified type that usually involves image tampering. In this study, a keypoint-based image forensics approach based on a superpixel segmentation algorithm and Helmert transformation has been proposed. The purpose of this approach is to detect copy-move forgery images and to obtain forensic information. The procedure of the proposed approach consists of the following phases. First, we extract the keypoints and their descriptors by using a scale-invariant feature transform (SIFT) algorithm. Then, based on the descriptor, matching pairs will be obtained by calculating the similarity between keypoints. Next, we will group these matching pairs based on spatial distance and geometric constraints via Helmert transformation to obtain the coarse forgery regions. Then, we refine these coarse forgery regions and remove mistakes or isolated areas. Finally, the forgery regions can be localized more precisely. Our proposed approach is a more robust solution for scaling, rotation, and compression forgeries. The experimental results obtained from testing different datasets demonstrate that the proposed method can obtain impressive precision/recall rates in comparison to state-of-the-art methods.

/pdf/copy-move-forgery-detection-for-image-forensics-using-the-44gl9md1ka.pdf

Copy-move forgery detection for image forensics using the superpixel segmentation and the Helmert transformation

In this paper, an approach for repairing the occluded human skeleton is proposed. Owing to the perception and record abilities of human beings inherently, people see at a glance that they can intuitively retrieve the moving action for any scene. Human being movement often has a self-occlusions or sheltered phenomenon when they walked. As for this occluded problem, so far, there is not a powerful method to solve, but it is very important scheme especially scene surveillance or patient cares. In order to solve this problem, we propose a skeleton repairing approach for the limbs-sheltered situation. This approach includes human skeleton capture based on the Kinect and natural interaction mechanism, skeleton database construction, and skeleton representation. Experimental results show that the rebuilt human skeleton is very close to the real skeleton like unsheltered state.

A Skeleton-Occluded Repair Method from Kinect

Image inpainting scheme is that repairs the damaged region of interest by user specified in an image. For the purpose of patching up automatically, filling in large-sized damaged areas in the image, and lowering down the operation complexity, we design a patch-based inpainting based on structure and texture as our main framework. To keep the structure consistency between the damaged areas and the non-damaged areas, we redefine two factors, confidence and illumination variation, which use to determine the priority of the filling order of target (damaged) regions. With these two defined factors, we propose an algorithm to obtain the best patch in each filling step for the target region. To solve the challenging problem of repairing structure in image completion, we design a novel image completion approach based on automatic salient structure propagation. Experimental results show that the proposed method can give good inpainting and visual quality.

A patch-based image inpainting based on structure consistence

The increasing popularity of the internet means that digital multimedia are transmitted more rapidly and easily. There is also a greater focus on intellectual property and copyright protection. To prevent piracy and other illegal activities, watermarking is a technique used to protect media data on the internet. An effective watermarking system based on a quantization index modulation (QIM) algorithm in the frequency domain is proposed to achieve copyright protection. The advantages of this approach are that it resists high JPEG compression ratios and maintains good image quality. The procedure consists of two steps: design of a robust embedding mechanism, and embedding and detection of the watermark. In the first step the robust embedding points and values for each image in the JPEG compression are identified. In the second step the QIM algorithm is used to insert a watermark into the image, and then a secure key is recorded. For detection, the embedded watermark is easily extracted using the secure key. Experiments demonstrate that the proposed technique can survive JPEG high compression ratios with good invisibility and robustness.

Hui-Yu Huang

Papers

A Video Watermarking Technique Based on Pseudo-3-D DCT and Quantization Index Modulation

Copy-move forgery detection for image forensics using the superpixel segmentation and the Helmert transformation

A Skeleton-Occluded Repair Method from Kinect

A patch-based image inpainting based on structure consistence

A Robust Watermarking Technique Resistant JPEG Compression