of a curved surface is the envelope of contour generators showing the boundary, at least locally, of the visible region swept out under viewer motion. In general, the outlines of curved surfaces (apparent contours) from di erent viewpoints are generated by di erent contour generators on the surface and hence do not provide a constraint on viewer motion. We show that points, however, have projec...

The silhouette of a smooth 3D object observed by a moving camera changes over time. Past work has shown how surface geometry can be recovered using the deformation of the silhouette when the camera motion is known. This paper addresses the problem of estimating both the full Euclidean surface structure and the camera motion from a dense set of silhouettes captured under orthographic or scaled o...

A family of qualitative methods is described that determine structure of curves in a scene from their image projections in two or more views. For example, plane curves are distinguished from space curves, and space curves from contour generators. The novelty of the approach is: rst, it is unaaected by camera intrinsic parameters, so calibration is not required; second, is it also unaaected by c...

This paper presents a method for computing the visual hull that is based on two novel representations: the rim mesh, which describes the connectivity of contour generators on the object surface; and the visual hull mesh, which describes the exact structure of the surface of the solid formed by intersecting a finite number of visual cones. We describe the topological features of these meshes and...

Image re-sampling according to epipolar geometry is a prerequisite for a variety of photogrammetric tasks such as stereoscopic observation. Executing stereoscopic observation by virtue of a pair of epipolar images is a common approach. This paper proposes a new approach to generate epipolar images and measure in stereoscopic environment. In order to improve the accuracy of stereoscopic observat...

Epipolar resampling is the procedure of eliminating vertical disparity between stereo images. Due to its importance, many methods have been developed in the computer vision and photogrammetry field. However, we argue that epipolar resampling of image sequences, instead of a single pair, has not been studied thoroughly. In this paper, we compare epipolar resampling methods developed in both fiel...

In this paper we present a unified approach of decomposing the fundamental and the essential matrix using information about epipoles. In contrast to other methods our approach is based on Householder transformations and can deal with finite and infinite epipoles. Our decomposition is able to yield a minimal parametrization of the fundamental and the essential matrix and retains their characteri...

We address the novel problem of detecting dynamic regions in CrowdCam images – a set of still images captured by a group of people. These regions capture the most interesting parts of the scene, and detecting them plays an important role in the analysis of visual data. Our method is based on the observation that matching static points must satisfy the epipolar geometry constraints, but computin...

In this paper, we propose a direct depth map acquisition method for a convergent camera array as well as a parallel camera array. Since image rectification is necessary for conventional stereo matching methods, disparity values are found in the same horizontal line of stereo images. Consecutively, the acquired disparity values are transformed to depth values. However, image rectification may le...

In this paper we address the problem of the recovery of a realistic textured model from an image sequence without any prior knowledge either about the parameters of the cameras, or about their motion. Firstly, using various computer vision tools, we establish correspondences between the image pairs and estimate the fundamental matrix. Secondly, using epipolar geometry constraints, we can obtain...