Video camera

About: Video camera is a research topic. Over the lifetime, 15118 publications have been published within this topic receiving 206329 citations.

Light field rendering

Abstract: A number of techniques have been proposed for flying through scenes by redisplaying previously rendered or digitized views. Techniques have also been proposed for interpolating between views by warping input images, using depth information or correspondences between multiple images. In this paper, we describe a simple and robust method for generating new views from arbitrary camera positions without depth information or feature matching, simply by combining and resampling the available images. The key to this technique lies in interpreting the input images as 2D slices of a 4D function the light field. This function completely characterizes the flow of light through unobstructed space in a static scene with fixed illumination. We describe a sampled representation for light fields that allows for both efficient creation and display of inward and outward looking views. We hav e created light fields from large arrays of both rendered and digitized images. The latter are acquired using a video camera mounted on a computer-controlled gantry. Once a light field has been created, new views may be constructed in real time by extracting slices in appropriate directions. Since the success of the method depends on having a high sample rate, we describe a compression system that is able to compress the light fields we have generated by more than a factor of 100:1 with very little loss of fidelity. We also address the issues of antialiasing during creation, and resampling during slice extraction. CR Categories: I.3.2 [Computer Graphics]: Picture/Image Generation — Digitizing and scanning, Viewing algorithms; I.4.2 [Computer Graphics]: Compression — Approximate methods Additional keywords: image-based rendering, light field, holographic stereogram, vector quantization, epipolar analysis

High performance imaging using large camera arrays

Abstract: The advent of inexpensive digital image sensors and the ability to create photographs that combine information from a number of sensed images are changing the way we think about photography. In this paper, we describe a unique array of 100 custom video cameras that we have built, and we summarize our experiences using this array in a range of imaging applications. Our goal was to explore the capabilities of a system that would be inexpensive to produce in the future. With this in mind, we used simple cameras, lenses, and mountings, and we assumed that processing large numbers of images would eventually be easy and cheap. The applications we have explored include approximating a conventional single center of projection video camera with high performance along one or more axes, such as resolution, dynamic range, frame rate, and/or large aperture, and using multiple cameras to approximate a video camera with a large synthetic aperture. This permits us to capture a video light field, to which we can apply spatiotemporal view interpolation algorithms in order to digitally simulate time dilation and camera motion. It also permits us to create video sequences using custom non-uniform synthetic apertures.

Graphical input controller and method with rear screen image detection

Abstract: An interactive graphics system includes a touch-sensitive controller having a number of semi-transparent light-diffusing panels imaged by a rear mounted imaging device such as a video camera. The imaging device is arranged to detect the shadows of objects, such as fingers, touching any of the panels. The camera can simultaneously to detect multiple touch points on the panels resulting from the touch of multiple fingers, which facilitates the detection of input gestures. The panel and the position on the panel touched can be determined by the position of the shadow on the video image. As the imaging device is only required to detect the existence of shadows on the panels, only a two-dimensional image must be processed. However, since the imaging device can image multiple panels simultaneously, a multi-dimensional input signal can be provided. Further, as this image is of high contrast, only light/dark areas must be differentiated for greatly simplified image processing.

Interactive control of avatars animated with human motion data

Abstract: Real-time control of three-dimensional avatars is an important problem in the context of computer games and virtual environments. Avatar animation and control is difficult, however, because a large repertoire of avatar behaviors must be made available, and the user must be able to select from this set of behaviors, possibly with a low-dimensional input device. One appealing approach to obtaining a rich set of avatar behaviors is to collect an extended, unlabeled sequence of motion data appropriate to the application. In this paper, we show that such a motion database can be preprocessed for flexibility in behavior and efficient search and exploited for real-time avatar control. Flexibility is created by identifying plausible transitions between motion segments, and efficient search through the resulting graph structure is obtained through clustering. Three interface techniques are demonstrated for controlling avatar motion using this data structure: the user selects from a set of available choices, sketches a path through an environment, or acts out a desired motion in front of a video camera. We demonstrate the flexibility of the approach through four different applications and compare the avatar motion to directly recorded human motion.

Machine dynamic selection of one video camera/image of a scene from multiple video cameras/images of the scene in accordance with a particular perspective on the scene, an object in the scene, or an event in the scene

Abstract: Each and any viewer of a video or a television scene is his or her own proactive editor of the scene, having the ability to interactively dictate and select--in advance of the unfolding of the scene and by high-level command--a particular perspective by which the scene will be depicted, as and when the scene unfolds. Video images of the scene are selected, or even synthesized, in response no a viewer-selected (i) spatial perspective on the scene, (ii) static or dynamic object appearing in the scene, or (iii) event depicted in the scene. Multiple video cameras, each at a different spatial location, produce multiple two-dimensional video images of the real-world scene, each at a different spatial perspective. Objects of interest in the scene are identified and classified by computer in these two-dimensional images. The two-dimensional images of the scene, and accompanying information, are then combined in the computer into a three-dimensional video database, or model, of the scene. The computer also receives a user/viewer-specified criterion relative to which criterion the user/viewer wishes to view the scene. From the (i) model and (ii) the criterion, the computer produces a particular two-dimensional image of the scene that is in "best" accordance with the user/viewer-specified criterion. This particular two-dimensional image of the scene is then displayed on a video display. From its knowledge of the scene and of the objects and the events therein, the computer may also answer user/viewer-posed questions regarding the scene and its objects and events.