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4D Reconstruction
In computer vision and computer graphics, 4D reconstruction is the process of capturing the shape and appearance of real objects along a temporal dimension.Dou, Mingsong, et al.Fusion4d: Real-time performance capture of challenging scenes" ACM Transactions on Graphics (TOG) 35.4 (2016): 1-13.Oswald, Martin Ralf, Jan Stühmer, and Daniel Cremers.Generalized connectivity constraints for spatio-temporal 3d reconstruction" European Conference on Computer Vision. Springer, Cham, 2014.Dong, Jing, et al.4D crop monitoring: Spatio-temporal reconstruction for agriculture" 2017 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2017. This process can be accomplished by methods such as depth camera imaging, photometric stereo, or structure from motion,Kyriakaki, Georgia, et al.4D reconstruction of tangible cultural heritage objects from web-retrieved images" International Journal of Heritage in the Digital Era 3.2 (2014): 431-451. and is also referred to as spatio-temporal r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth Camera
Range imaging is the name for a collection of techniques that are used to produce a 2D image showing the distance to points in a scene from a specific point, normally associated with some type of sensor device. The resulting range image has pixel values that correspond to the distance. If the sensor that is used to produce the range image is properly calibrated the pixel values can be given directly in physical units, such as meters. Types of range cameras The sensor device that is used for producing the range image is sometimes referred to as a ''range camera'' or ''depth camera''. Range cameras can operate according to a number of different techniques, some of which are presented here. Stereo triangulation Stereo triangulation is an application of stereophotogrammetry where the depth data of the pixels are determined from data acquired using a stereo or multiple-camera setup system. This way it is possible to determine the depth to points in the scene, for example, from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometric Stereo
Photometric stereo is a technique in computer vision for estimating the surface normals of objects by observing that object under different lighting conditions. It is based on the fact that the amount of light reflected by a surface is dependent on the orientation of the surface in relation to the light source and the observer. By measuring the amount of light reflected into a camera, the space of possible surface orientations is limited. Given enough light sources from different angles, the surface orientation may be constrained to a single orientation or even overconstrained. The technique was originally introduced by Woodham in 1980.Woodham, R.J. 1980Photometric method for determining surface orientation from multiple images Optical Engineerings 19, I, 139-144. The special case where the data is a single image is known as shape from shading, and was analyzed by B. K. P. Horn in 1989.B. K. P. Horn, 1989. Obtaining shape from shading information. In B. K. P. Horn and M. J. Broo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure From Motion
Structure from motion (SfM) is a photogrammetric range imaging technique for estimating three-dimensional structures from two-dimensional image sequences that may be coupled with local motion signals. It is studied in the fields of computer vision and visual perception. In biological vision, SfM refers to the phenomenon by which humans (and other living creatures) can recover 3D structure from the projected 2D (retinal) motion field of a moving object or scene. Principle Humans perceive a great deal of information about the three-dimensional structure in their environment by moving around it. When the observer moves, objects around them move different amounts depending on their distance from the observer. This is known as motion parallax, and from this depth information can be used to generate an accurate 3D representation of the world around them. Finding structure from motion presents a similar problem to finding structure from stereo vision. In both instances, the correspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D Reconstruction
In computer vision and computer graphics, 3D reconstruction is the process of capturing the shape and appearance of real objects. This process can be accomplished either by active or passive methods. If the model is allowed to change its shape in time, this is referred to as spatio-temporal reconstruction, non-rigid or spatio-temporal reconstruction. Motivation and applications The research of 3D reconstruction has always been a difficult goal. By Using 3D reconstruction one can determine any object's 3D profile, as well as knowing the 3D coordinate of any point on the profile. The 3D reconstruction of objects is a generally scientific problem and core technology of a wide variety of fields, such as Computer Aided Geometric Design (CAGD), computer graphics, computer animation, computer vision, medical imaging, computational science, virtual reality, digital media, etc. For instance, the lesion information of the patients can be presented in 3D on the computer, which offers a new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Viewpoint Television
Free viewpoint television (FTV) is a system for viewing natural video, allowing the user to interactively control the viewpoint and generate new views of a dynamic scene from any 3D position. The equivalent system for computer-simulated video is known as virtual reality. With FTV, the focus of attention can be controlled by the viewers rather than a director, meaning that each viewer may be observing a unique viewpoint. It remains to be seen how FTV will affect television watching as a group activity. History Systems for rendering arbitrary views of natural scenes have been well known in the computer vision community for a long time but only in recent years has the speed and quality reached levels that are suitable for serious consideration as an end-user system. Professor Masayuki Tanimoto from Nagoya University (Japan) has done much to promote the use of the term "free viewpoint television" and has published many papers on the ray space representation, although other technique ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure From Motion
Structure from motion (SfM) is a photogrammetric range imaging technique for estimating three-dimensional structures from two-dimensional image sequences that may be coupled with local motion signals. It is studied in the fields of computer vision and visual perception. In biological vision, SfM refers to the phenomenon by which humans (and other living creatures) can recover 3D structure from the projected 2D (retinal) motion field of a moving object or scene. Principle Humans perceive a great deal of information about the three-dimensional structure in their environment by moving around it. When the observer moves, objects around them move different amounts depending on their distance from the observer. This is known as motion parallax, and from this depth information can be used to generate an accurate 3D representation of the world around them. Finding structure from motion presents a similar problem to finding structure from stereo vision. In both instances, the correspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volumetric Video
Volumetric capture or volumetric video is a technique that captures a three-dimensional space, such as a location or performance. This type of volumography acquires data that can be viewed on flat screens as well as using 3D displays and VR goggles. Consumer-facing formats are numerous and the required motion capture techniques lean on computer graphics, photogrammetry, and other computation-based methods. The viewer generally experiences the result in a real-time engine and has direct input in exploring the generated volume. History Recording talent without the limitation of a flat screen has been depicted in science-fiction for a long time. Holograms and 3D real-world visuals have featured prominently in ''Star Wars'', ''Blade Runner'', and many other science-fiction productions over the years. Through the growing advancements in the fields of computer graphics, optics, and data processing, this fiction has slowly evolved into a reality. Volumetric video is the logical next ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Graphics
Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven by computer graphics hardware. It is a vast and recently developed area of computer science. The phrase was coined in 1960 by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, or typically in the context of film as computer generated imagery (CGI). The non-artistic aspects of computer graphics are the subject of computer science research. Some topics in computer graphics include user interface design, sprite graphics, rendering, ray tracing, geometry processing, computer animation, vector graphics, 3D modeling, shaders, GPU design, implicit surfaces, visualization, scientific c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
