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This paper proposes a novel technique to calibrate a network of cameras by fusion of inertial-visual data. There is a set of still cameras (structure) and one (or more) mobile agent(s) camera in the network. Each camera within the network is assumed to be rigidly coupled with an Inertial Sensor (IS). By fusion of inertial and visual data, it becomes possible to consider a virtual camera beside of...
The camera calibration problem consists in estimating the intrinsic and the extrinsic parameters. This problem can be solved by computing the fundamental matrix. The fundamental matrix can be obtained from a set of corresponding points. However in practice, corresponding points may be inaccurately estimated, falsely matched or badly located, due to occlusion and ambiguity, among others. On the other...
In recent years, there has been increased interest in characterizing and extracting 3D information from video sequences for object tracking and identification. In this paper, we propose a single view-based framework for robust estimation of height and position. In this work, 2D features of a target object is back-projected into the 3D scene space where its coordinate system is given by a rectangular...
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...
With the development of Chinese planes, the examination technology of wind tunnels also improves in gradually. From the simulation ability of the wind tunnel examination to the data's accuracy, there is a very high demand for aircraft. In the examination of wind tunnel, the displacement measurement of aircraft model is an important index, and a slight variation on the measurement often causes tremendous...
In this paper, we present that determining camera intrinsic and pose parameters based on concentric circles via planar structure, then using circular points constraint camera intrinsic parameters by linear methods. Meanwhile to obtain camera pose parameters, we employ two orthogonal vanishing points on the images and hypothesis arbitrary point on the image is corresponded to the origin of the 3D world...
A catadioptric system consisting of a pinhole camera and two planar mirrors is deeply investigated in this paper. The two mirrors combine to form a corner and face-to-face with the pinhole. Their relative pose is unknown. An object will be reflected in the mirror corner one-time or multiple-times. Using the pinhole, we may take an image containing the object and its reflections, i.e., simultaneously...
Cameras are getting smaller and cheaper. So a cost-effective usage of multi-camera systems in vehicles gets more and more attractive. In many cases it is desirable to cover the whole environment all around the vehicle. But often design restrictions and energy consumption do not allow constellations of cameras with overlapping field of views. However, for a common and geometric usage of the extracted...
In this paper, we propose a method for calibrating relative position and orientation of multiple unsynchronized cameras from general moving points. If the sampling times of multiple cameras are different from each other, there is no corresponding point in the images of moving points and we cannot calibrate these cameras. In this paper we analyze geometric relationships of multiple cameras in the frequency...
Fiducial marker systems consist of unique patterns mounted in the environment and computer vision algorithms that help automatically find features in digital camera images. They are useful for Augmented Reality (AR), robot navigation, 3D modeling, and other applications. In this paper we introduce an extension of marker-based approaches. For some applications which need a large working space, we mounted...
Reprojection error is a commonly used measure for comparing the quality of different camera calibrations, for example when choosing the best calibration from a set. While this measure is suitable for single cameras, we show that we can improve calibrations in a binocular or multi-camera setup by calibrating the cameras in pairs using a rectification error. The rectification error determines the mismatch...
The article represents a method to perform the Shape From Silhouette (SFS) of human, based on gravity sensing. A network of cameras is used to observe the scene. The extrinsic parameters among the cameras are initially unknown. An IMU is rigidly coupled to each camera in order to provide gravity and magnetic data. By applying a data fusion between each camera and its coupled IMU, it becomes possible...
This paper describes the development of a vehicle's orientation measurement system using a single camera. We applied a single camera calibration method using a planar pattern to measure the orientation from the camera to a planar object. With this technique, the orientation from camera to planar object can be obtained when using feature coordinates of more than 4 points on a planar object image. We...
A global calibration method based on combined 3D target is proposed to solve the calibration problem of two sensors vision system without common view field. The combined 3D target is consisted of two planar targets, which are placed freely according to the sensors' positions. By translating the 3D target properly, the closed-form solution of the transformation from one local camera coordinate frame...
We present a novel calibration technique for all central catadioptric cameras using images of planar grids. We adopted the well-known sphere camera model to describe the catadioptric projection. We show that, using the so-called lifted coordinates, a linear relation mapping the grid points to the corresponding points on the image plane can be written as a 6 × 6 matrix Hcata, which acts like the classical...
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...
The key of camera calibration is to calculated the initial value of extrinsic and intrinsic camera parameters. Since the calculation of initial value is not a purely linear problem, 3D measurement products are often using a fixed focal length camera calibration method, but the measuring exists the problem of inconvenience of usage and a limited measurement-range. We have derived a novel camera calibration...
In this paper, we propose augmented reality (AR) applications for equipment maintenance. The system is based on the projection and detection of infrared markers. We use an infrared projector to project markers onto the surface of the equipment to be maintained. These markers are invisible to the human-eye, but they could be clearly identified by the infrared camera. As a proof of concept, we have...
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...
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