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In this paper, a novel method of the 2D Euclidean structure recovery in one view from the projections of N parallel conics is proposed. Without considering the conic dual to the absolute points (CDAP), we transform conic features from the homogeneous coordinates to the lifted coordinates. In the lifted space, the conic features have the similar properties to the point or line features, which especially...
We achieve a precise camera calibration using circular control points by, first, separation of the lens distortion parameters from other camera parameters and computation of the distortion field in advance by using a calibration harp. Second, in order to compensate for perspective bias, which is prone to occur when using a circled pattern, we incorporate conic affine transformation into the minimization...
Concentric circles (C2Tag's) are planar markers which offer great advantages for detection and tracking. As the circular point-pair (CPP) is the geometric information encoded by a C2Tag, this work is focused on factorization techniques for Structure-and-Motion from multiple CPP images. Gathering all of them in a measurement matrix, two issues are addressed: how to scale the existing entries and how...
The paper presents a new closed-form solution to estimate focal length and extrinsic parameters from a single calibration image. Firstly, a new backward camera model which is based on plane equation of calibration panel in 3D space is introduced, and three indirect extrinsic parameters are used to determine the final extrinsic parameter. Based on this model and distance between neighboring control...
This article deals with a simple and flexible extrinsic calibration method, for non-overlapping camera rig. The cameras do not see the same area at the same time. They are rigidly linked and can be moved. The most representative application is the mobile robotics domain. The calibration procedure consists in maneuvering the system while each camera observes a static scene. A linear solution derived...
According to planar projective transformation theory, a calibration method of the three dimensional (3D) laser measurement system is put forward to application in this paper. A key contribution of the method lies in the derivation of transformation relations that describe the same point in three defined coordinate systems with respect to the rotating characteristic of two scanning planes and its calibration...
In this work, we present a robust method for automatic recalibration camera pose via homography. And assuming that the intrinsic parameters of the camera are known from initial calibration, then we show that its translation vector and rotation matrix via Homography. In this method, computational cost is low compared with traditional methods. Some simulations and real data experiments show the accuracy...
This work addresses the problems of (i) self-calibration of a moving camera observing a 3D scene composed by planar structures and (ii) scene segmentation and reconstruction. Although there exist some works intending to deal with these problems, most of them are based on the estimation of the epipolar geometry, non-linear optimization, or linear systems that do not incorporate geometrical consistency...
We present a novel calibration method for multi-camera platforms, based on multi-linear constraints. The calibration method can recover the relative orientation between the different cameras on the platform, even when there are no corresponding feature points between the cameras, i.e. there are no overlaps between the cameras. It is shown that two translational motions in different directions are...
This paper presents a novel method for calibrating line-scan cameras using a calibration pattern comprising two parallel planes with lines that can be described using known equations. Using pattern geometry and a line that is captured by a line-scan camera, we calculate the 3-D coordinates of the points corresponding to the straight lines of a pattern that is captured by the line-scan camera. These...
We introduce a formulation for ??orthogonal calibration?? which is to extract camera calibration parameters from the world coordinates with unknown heights. Such coordinates can be obtained from an aerial photograph or a GPS device. A typical approach would be to introduce a planar surface assumption and apply the plane homography. However, the planar assumption often fails; moreover, the camera parameters...
In order to make the calibration convenient, this paper proposed a new easy calibrating target plane. This method based on circular point theory. The target plane consists of a triangle and some lines. We take photos of the target from different position, and then calculate the circular points by Laugerre theory. The intrinsic and extrinsic parameters can be determined. This method is simple and based...
In this paper we address the problem of geometric calibration of video projectors. Like in most previous methods we also use a camera that observes the projection on a planar surface. Contrary to those previous methods, we neither require the camera to be calibrated nor the presence of a calibration grid or other metric information about the scene. We thus speak of geometric auto-calibration of projectors...
This paper discusses the constraints of coplanar points in perspective projection, based on which a new method to calibrate lens distortion is presented. Stem from the concept of center line related to Ponceletpsilas theorem on projective geometry, an equation of the center line is derived algebraically, from which some useful properties of the center line are deduced. These properties constitute...
Novel methods are proposed for self-calibrating a pure-rotating camera using semidefinite programming (SDP). Key to the approach is the use of the positive-definiteness requirement for the dual image of the absolute conic (DIAC). The problem is couched within a convex optimization framework and convergence to the global optimum is guaranteed. Experiments on various data sets indicate that the proposed...
In this article, we present the projective equation of a circle in a perspective view, which naturally encodes such important geometric entities as the projected circle center, the vanishing point of the normal direction of the circlepsilas supporting plane and the degenerate conic envelope spanned by the image of circular points (ICPs). Based on this projective equation, we propose an easy technique...
In this paper, we propose a new calibration method for projector-camera systems. The projector-camera systems have been studied extensively as one of new information presenting systems. For calibrating the systems, we in this paper use virtual mutual projections between a camera and a projector. We first show that by using a shadow of the camera, we can generate mutual projection between a camera...
A calibration method for a structured light system by observing a planar object from unknown viewpoints is proposed. A structured light system captures a 3D shape by a camera that observes a light stripe on an object illuminated by a projector. The 3D shape, obtained from the system defined by a pinhole model for the projection of a light stripe, is solved using the equation of a plane model for the...
A measurement technique about coordinate of space points based on digital close range photogrammetry was investigated. Two kinds of reference points were placed on the object surface to determinate their spatial position by identifying and detecting. Several key techniques, including code and decode, calibration of the camera, camera orientating technique, high precise image processing algorithm were...
A new calibration algorithm for multi-camera systems using the 1D calibration objects is proposed. The algorithm integrates the rank-4 factorization with Zhangpsilas method. The intrinsic parameters as well as the extrinsic parameters are recovered only by capturing with cameras the 1D objectpsilas rotations around a fixed point. The algorithm is based on factorization of the scaled measurement matrix,...
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