About: Scan line is a research topic. Over the lifetime, 4089 publications have been published within this topic receiving 52733 citations. The topic is also known as: National Television System Committee.
TL;DR: A new object-order rendering algorithm based on the factorization of a shear-warp factorization for perspective viewing transformations is described that is significantly faster than published algorithms with minimal loss of image quality.
Abstract: Several existing volume rendering algorithms operate by factoring the viewing transformation into a 3D shear parallel to the data slices, a projection to form an intermediate but distorted image, and a 2D warp to form an undistorted final image. We extend this class of algorithms in three ways. First, we describe a new object-order rendering algorithm based on the factorization that is significantly faster than published algorithms with minimal loss of image quality. Shear-warp factorizations have the property that rows of voxels in the volume are aligned with rows of pixels in the intermediate image. We use this fact to construct a scanline-based algorithm that traverses the volume and the intermediate image in synchrony, taking advantage of the spatial coherence present in both. We use spatial data structures based on run-length encoding for both the volume and the intermediate image. Our implementation running on an SGI Indigo workstation renders a 2563 voxel medical data set in one second. Our second extension is a shear-warp factorization for perspective viewing transformations, and we show how our rendering algorithm can support this extension. Third, we introduce a data structure for encoding spatial coherence in unclassified volumes (i.e. scalar fields with no precomputed opacity). When combined with our shear-warp rendering algorithm this data structure allows us to classify and render a 2563 voxel volume in three seconds. The method extends to support mixed volumes and geometry and is parallelizable.
TL;DR: An algorithm to detect depth discontinuities from a stereo pair of images is presented, which handles large untextured regions, uses a measure of pixel dissimilarity that is insensitive to image sampling, and prunes bad search nodes to increase the speed of dynamic programming.
Abstract: An algorithm to detect depth discontinuities from a stereo pair of images is presented. The algorithm matches individual pixels in corresponding scanline pairs, while allowing occluded pixels to remain unmatched, then propagates the information between scanlines by means of a fast postprocessor. The algorithm handles large untextured regions, uses a measure of pixel dissimilarity that is insensitive to image sampling, and prunes bad search nodes to increase the speed of dynamic programming. The computation is relatively fast, taking about 600 nanoseconds per pixel per disparity on a personal computer. Approximate disparity maps and precise depth discontinuities (along both horizontal and vertical boundaries) are shown for several stereo image pairs containing textured, untextured, fronto-parallel, and slanted objects in indoor and outdoor scenes.
TL;DR: This paper presents a GPU-based stereo matching system with good performance in both accuracy and speed, and is the top performer in the Middlebury benchmark, and the results are achieved on GPU within 0.1 seconds.
Abstract: This paper presents a GPU-based stereo matching system with good performance in both accuracy and speed. The matching cost volume is initialized with an AD-Census measure, aggregated in dynamic cross-based regions, and updated in a scanline optimization framework to produce the disparity results. Various errors in the disparity results are effectively handled in a multi-step refinement process. Each stage of the system is designed with parallelism considerations such that the computations can be accelerated with CUDA implementations. Experimental results demonstrate the accuracy and the efficiency of the system: currently it is the top performer in the Middlebury benchmark, and the results are achieved on GPU within 0.1 seconds. We also provide extra examples on stereo video sequences and discuss the limitations of the system.
TL;DR: In this paper, a method and apparatus for in-band, video broadcasting of commands to interactive devices is described, where control data are encoded by subliminally modulating, prior to the remote, composite video broadcast of video program material, a selected sequence of video image fields.
Abstract: Method and apparatus for in-band, video broadcasting of commands to interactive devices are described. Control data are encoded by subliminally modulating, prior to the remote, composite video broadcast of video program material, a selected sequence of video image fields. The resulting modulated video fields within the viewing area of a television, each having alternately, proportionately raised and lowered luminance horizontal scan lines, are monitored by a light sensitive device positioned adjacent the user's television screen. A semirigid, twisted pair cable connects the device to nearby receiver/transmitter electronics that discriminate the binary data from the program material and amplitude modulate a high frequency infrared (IR) carrier with the data. Interactive devices, e.g. educational aids or action toys, within range of the wireless IR transmission detect energy in this frequency range, decode the commands embedded in the control data, and selectively execute predetermined actions in response to the data-encoded broadcast. In a proposed modification, low radio frequency (RF) electromagnetic radiation emanating from the television's raster scan electronics is coupled by a conventional RF antenna to the receiver electronics, which identically discriminate the binary data, from the program material, for transmission to the interactive devices.
TL;DR: The design, application, and evaluation of parallel processing to the high-speed volumetric ultrasound imaging system, which uses pulse-echo phased array principles to steer a 2-D array transducer of 289 elements in a pyramidal scan format is described.
Abstract: For pt.I see ibid., vol.38, no.2, p.100-8 (1991). The authors describe the design, application, and evaluation of parallel processing to the high-speed volumetric ultrasound imaging system. The scanner produces images analogous to an optical camera or the human eye and supplies more information than conventional sonograms. Potential medical applications include improved anatomic visualization, tumor localization, and better assessment of cardiac function. The system uses pulse-echo phased array principles to steer a 2-D array transducer of 289 elements in a pyramidal scan format. Parallel processing in the receive mode produces 4992 scan lines at a rate of approximately 8 frames/s. Echo data for the scanned volume is presented online as projection images with depth perspective, stereoscopic pairs, or multiple tomographic images. The authors also describe the techniques developed for the online display of volumetric images on a conventional CRT oscilloscope and show preliminary volumetric images for each display mode. >