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This paper presents a method to detect and construct a 3D geometric model of an urban area with complex buildings using aerial LIDAR (Light Detection and Ranging) data. The LIDAR data collected from a nadir direction is a point cloud containing surface samples of not only the building roofs and terrain but also undesirable clutter from trees, cars, etc. The(More)
Multiple images of a scene are related through 2D/3D view transformations and linear and non-linear camera transformations. In the traditional techniques to compute these transformations, especially the ones relying on direct intensity gradients, one image and its coordinate system have been assumed to be ideal and distortion free. In this paper, we present(More)
The problem of piecing together individual frames in a video sequence to create seamless panoramas (video mosaics) has attracted increasing attention in recent times. One challenge in this domain has been to rapidly and automatically create high quality seamless mosaics using inexpensive cameras and relatively free hand motions. In order to capture a wide(More)
Recently, there has been a growing interest in the use of mosaic images to represent the information contained in video sequences. This paper systematically investigates how to go beyond thinking of the mosaic simply as a visualization device, but rather as a basis for an eecient and complete representation of video sequences. We describe two diierent types(More)
Decomposing video frames into coherent two-dimensional motion layers is a powerful method for representing videos. Such a representation provides an intermediate description that enables applications such as object tracking, video summarization and visualization, video insertion, and sprite-based video compression. Previous work on motion layer analysis has(More)
Tracking unknown number of moving objects in cluttered scenes is an important yet difficult research issue in computer vision. Two fundamental problems encountered are high-dimensional parameter space and complicated situations such as object addition, deletion, and occlusion. The recently proposed CONDENSATION algorithm and its variants enable the(More)
We present a novel building segmentation system for densely built areas, containing thousands of buildings per square kilometer. We employ solely sparse LIDAR (Light/Laser Detection Ranging) 3D data, captured from an aerial platform, with resolution less than one point per square meter. The goal of our work is to create segmented and delineated buildings as(More)
This paper presents an algorithmic approach to the problem of detecting independently moving objects in 3D scenes that are viewed under camera motion. There are two fundamental constraints that can be exploited for the problem : (i) two/multi-view camera motion constraint (for instance, the epipolar/trilinear constraint) and (ii) shape constancy constraint.(More)
Videos and 3D models have traditionally existed in separate worlds and as distinct representations. Although texture maps for 3D models have been traditionally derived from multiple still images, real-time mapping of live videos as textures on 3D models has not been attempted. This paper presents a system for rendering multiple live videos in real-time over(More)