4,311 research outputs found
Hierarchical structure-and-motion recovery from uncalibrated images
This paper addresses the structure-and-motion problem, that requires to find
camera motion and 3D struc- ture from point matches. A new pipeline, dubbed
Samantha, is presented, that departs from the prevailing sequential paradigm
and embraces instead a hierarchical approach. This method has several
advantages, like a provably lower computational complexity, which is necessary
to achieve true scalability, and better error containment, leading to more
stability and less drift. Moreover, a practical autocalibration procedure
allows to process images without ancillary information. Experiments with real
data assess the accuracy and the computational efficiency of the method.Comment: Accepted for publication in CVI
Certifying the Existence of Epipolar Matrices
Given a set of point correspondences in two images, the existence of a
fundamental matrix is a necessary condition for the points to be the images of
a 3-dimensional scene imaged with two pinhole cameras. If the camera
calibration is known then one requires the existence of an essential matrix.
We present an efficient algorithm, using exact linear algebra, for testing
the existence of a fundamental matrix. The input is any number of point
correspondences. For essential matrices, we characterize the solvability of the
Demazure polynomials. In both scenarios, we determine which linear subspaces
intersect a fixed set defined by non-linear polynomials. The conditions we
derive are polynomials stated purely in terms of image coordinates. They
represent a new class of two-view invariants, free of fundamental
(resp.~essential)~matrices
Creating virtual models from uncalibrated camera views
The reconstruction of photorealistic 3D models from camera views is becoming an ubiquitous element in many applications that simulate physical interaction with the real world. In this paper, we present a low-cost, interactive pipeline aimed at non-expert users, that achieves 3D reconstruction from multiple views acquired with a standard digital camera. 3D models are amenable to access through diverse representation modalities that typically imply trade-offs between level of detail, interaction, and computational costs. Our approach allows users to selectively control the complexity of different surface regions, while requiring only simple 2D image editing operations. An initial reconstruction at coarse resolution is followed by an iterative refining of the surface areas corresponding to the selected regions
Recursive Estimation of Camera Motion from Uncalibrated Image Sequences
In This memo we present an extension of the motion estimation scheme presented in a previous CDS technical report [14, 16], in order to deal with image sequences coming from an uncalibrated camera. The scheme is based on some results in epipolar geometry and invariant theory which can be found in [6]. Experiments are performed on noisy synthetic images
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