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Camera calibration is to confirm the camera's geometrical and optical parameter, as well as the orientation of the camera frame relative to world coordinate system. There are various calibration methods in different fields. Based on seven styles standards, paper analyzes and compares those methods systemically, then interesting avenues for future research are proposed.
In this paper we present the research activity carried out in the integration of 2D and 3D vision systems into robot cells, to improve their performance in typical pick and place operations. Two projects have been developed: the former is the combination of a 2D vision system based on two cameras with a two-robot cell. The latter consists of the integration of a laser slit - based optical head in...
Above all, we pointed out that the basis of the calibration algorithm based on the grid points is the matrix, which indicates the mapping relationship between the target surface and the image surface. But to our disappointment, it is the correspondence problem of the calibration points that exists in the current way to calculate it. Therefore, the fiducial marker system is used for reference here,...
Camera parameters estimation is an important issue in machine vision research area. This paper proposes a new method to find pan and tilt of camera in sport scene on the basis of vanishing points. Vanishing point (VP) of parallel lines is the image of the point at infinity, which corresponds to the projection of the intersection of parallel lines at infinity. According to projective geometry constraint,...
Self-calibration for imaging sensors is essential to many computer vision applications. In this paper, a novel algorithm based on multiple view self-calibration and metric reconstruction is proposed for structured light system. In the method, the camera is implemented in three different positions to acquire images. This algorithm can be applied in various occasions with its simple calculation and...
Camera parameters estimation is an important issue in machine vision. This paper proposes a new method to find translation and rotation matrix of camera in sport scene on the basis of vanishing points. Vanishing point (VP) of parallel lines is the image of the point at infinity, which corresponds to the projection of the intersection of parallel lines at infinity. According to projective geometry...
The paper presents an active vision system for the detection of dangerous fall events and the recognition of four main human postures (lie, sit, stand, bend) in Ambient Assisted Living applications. The suggested vision system uses a Time-Of-Flight camera providing accurate 3D measurements of the scene in all illumination conditions. In order to accommodate different installation setups, the system...
The paper presents an active vision system for the automatic detection of falls and the recognition of several postures for elderly homecare applications. A wall-mounted Time-Of-Flight camera provides accurate measurements of the acquired scene in all illumination conditions, allowing the reliable detection of critical events. Preliminarily, an off-line calibration procedure estimates the external...
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...
A new approach based on BP neural network for seeking-solution projection matrix of camera is presented in this thesis. The network structure is designed according to camera mathematical model, where there are 4 inputs composed of the sampled points' coordinates in world coordinate system and constant 1, and 2 outputs are obtained, expected values of which are elements of constant vector [0, 0]T....
Solving visual features' correspondence and dealing with missing data are two factors of limitations for points registration techniques. To tackle this problem, we conceived a pattern, primarily designed for structured lighting vision systems, which may also be used for camera calibration purposes. The pattern design previously presented provides a huge of benefits. Among them, we firstly present...
This study presents a low-cost scanning system for acquiring 3D geometry and texture information of large objects and for performing multi-scanning patch registration to obtain a whole realistic 3D model. The proposed system is composed of a line-stripe laser and a color CCD camera. The scanning processes consist of three steps. In the first step, the 3D depth information of the scanned object is...
In the field of machine vision, camera calibration refers to the experimental determination of a set of parameters which describe the image formation process for a given analytical model of the machine vision system. An accurate, reliable calibration procedure is essential for most industrial machine vision applications including mechanical metrology, robot assembly, reverse engineering, stereo vision...
Object recognition techniques are well known in the field of machine vision, and aim at the classification of certain observed rigid objects based on the information acquired by a specific sensor. These techniques can either be performed in the 2D image space by simply applying suitable image processing algorithms, or in the real world 3D space by performing surface reconstruction of the object's...
To solve the problem of global calibration for multi-binocular vision sensor in a wide measuring range, a method based on 1D target is presented. The 1D target is only required to be put in a number of proper positions between two vision sensors so that one sensor can observe one end feature point and the other sensor can observe the other end point. These two sensors need not to have common vision...
In active vision system, the linear illumination and vidicon sampling are widely used in obtaining the 3-D information of the objects surface distance and direction. In order to have the accurate data, we need to calibrate the optics sensor. In this paper, an optimized non-linear method was adopted to calibrate the sensor, and the mathiematics model of the method was very close to the actual performance...
In this paper, new approaches to track and measure a moving object in 3D space are presented with a binocular camera system. As the moving object out of the field of view, one or two cameras of the pan-tilt binocular system are controlled to search the object, and compute its position in a world coordinate system. Tracking and measuring of a specified object can be done in real time as the cameras...
Camera calibration is an important issue in machine vision. This paper proposes an improved calibration based on vanishing point to determine camera intrinsic parameters as well as its pose. According to projective geometry constraint, we compute all camera parameters directly by two vanishing points. Compared with existing methods based on vanishing point, the proposed approach decreases variables...
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