An Overview of Digital Video Watermarking

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 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 study and propose some future research directions

Robust DT CWT Based DIBR 3D Video Watermarking using Chrominance Embedding

The popularity of 3D video is increasing daily due to the availability of low-cost 3D televisions and high-speed Internet access. However, currently the contents of 3D video can be distributed illegally without any protection. For views generated using a depth-image-based rendering technique, not only the left and right views can be distributed as 3D content, but also the center, left, or right views individually as 2D content. As digital video watermarking is a possible way of protecting these views from unauthorized distribution, in this paper, we propose a digital watermarking method for depth-image-based rendered 3D video. In this method, the watermark is embedded in both of the chrominance channels of a YUV representation of the center view using the dual-tree complex wavelet transform. Then, the left and right views are generated from the watermarked center view and depth map using a depth-image based rendering technique. Finally, the watermark can be extracted from the center, left, and right views in a blind fashion without using the original unwatermarked center, left, or right views. This watermark is robust to geometric distortions, such as upscaling, rotation and cropping, downscaling to an arbitrary resolution, and the most common video distortions, including lossy compression and additive noise. Due to the approximate shift invariance characteristic of the dual-tree complex wavelet transform, the technique is robust against distortions in the left and right views generated using depth-image based rendering. The proposed method can also survive baseline distance adjustment and both 2D and 3D camcording

3D-Mapping for Visualisation of Rigid Structures: A Review and Comparative Study

In this review, we discuss state-of-the-art developments in 3D models for small and rigid structures. This includes the pros and cons of cutting-edge range cameras used as active 3D scanners, while also considering passive image reconstruction schemes by means of the well-known structure-from-motion (SfM) algorithms. Furthermore, we discuss the issue of how data fusion algorithms can be used to optimally fuse 2D contour information onto 3D models for several different applications. Considering the benefits of 3D range sensors, we also review current trends in optimum data fusion of point clouds from 3D range sensors. We present the benefits and the limitations of each algorithm against various design considerations. To highlight the pros and cons, we also perform a comparative study of the performance of a 3D range sensor, represented by an iPad structure sensor, with respect to the well-known SfM software packages, namely, Bundler, Microsoft PhotoSynth, Agisoft PhotoScan, and Smart3DCapture. Last, we highlight several research opportunities and potential research challenges associated with each technique

Eighth International Conference on Digital Image Processing (ICDIP 2016)

Whiplash-associated disorder (WAD) is a commonly occurring injury that often results from neck trauma suffered in car accidents. However the cause of the condition is still unknown and there is no definitive clinical test for the presence of the condition. Researchers have begun to analyze the size of neck muscles and the presence of fatty infiltrates to help understand WAD. However this analysis requires a high precision delineation of neck muscles which is very challenging due to a lack of distinctive features in neck magnetic resonance imaging (MRI). This paper presents a novel atlas-based neck muscle segmentation method which employs discrete cosine-based elastic registration with affine initialization. Our algorithm shows promising results based on clinical data with an average Dice similarity coefficient (DSC) of 0.84±0.0004

Stereo vision-based 3D positioning and tracking

The evolution of technologies for the capture of human movement has been motivated by a number of potential applications across a wide variety of fields. However, capturing human motion in 3D is difficult in an outdoor environment when it is performed without controlled surroundings. In this paper, a stereo camera rig with an ultra-wide baseline distance and conventional cameras with fish-eye lenses is proposed. Its cameras provide a wide field of view (FOV) which increases the coverage area and also enables the baseline distance to be increased to cover the common area required for both cameras’ views to perform as a stereo camera. We propose a passive marker-based approach to track the motion of the object. In this method, an adaptive thresholding method is applied to extract each small pink polyester marker from the video frames. As the cameras have fish-eye lenses, it is difficult to estimate the depth information using a pinhole camera model. We use a unique method to restore the 3D positions by developing a relationship between the pixel dimensions and distances in an image and real world coordinates. In this paper, occlusion detection is considered because, in the marker-based capturing of articulated human kinematics, the occlusion of a marker is one of the major challenges. The detection algorithm differentiates among types of occlusions and predicts any missing marker position where necessary. As this design is intended to be mounted on a moving carrier, such as a drone or car, a method for compensating the camera’s ego-motion is proposed. The proposed 3D positioning and tracking system is tested in different situations to validate its applicability as a stereo camera rig as well as its performance for motion capture. The performance of the proposed system is compared with that of a standard motion capture system called Vicon and is shown to have the same order of accuracy while incurring less cost