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A nonlinear camera model with one order radial distortion is established for the GRB-400 robot vision system in this paper. Firstly, the coordinates of the calibrated image are collected by Matrox image acquisition card, and then distortion parameters of camera are worked out by the established linear equation based on radial alignment constraint (RAC). The image is corrected by the distortion parameters,...
The paper describes a calibration procedure for a structured-light sinusoidal-fringe profilometer which requires the acquisition of images of a plane in one or more unknown poses when it is illuminated by sinusoidal fringe patterns projected by an illuminator. The procedure does not require specific target but only a planar surface which can be freely moved or rotated around a vertical axis.
Neural networks was used in the camera calibration of binocular stereo vision, segmentation and recognition of fruit or vegetable images, fruit or vegetable classification, orientation error amendment of fruit or vegetable, obstacle avoidance of robot manipulator, sensor data fusion about fruit and vegetable harvesting robot. The research results in all the aspects mentioned above of fruit and vegetable...
This paper, presents a tracking technique based on both detection Color marker and a least squares method. The objective is to estimate the perspective transformation matrix for the current view of the camera. This technique does not require any information or computation of the camera parameters; it can be used in real time without any initialization and the user can change the camera focal without...
To achieve the calibration parameters of vision measurement system, this paper presents a new camera calibration method based on grid recognition. The calibration is implemented by acquiring the corresponding relations between the world coordinates and pixel coordinates of the planar gridding target image captured by camera. Meanwhile, the pixel coordinates of the target image are detected separately...
Camera calibration is becoming a latest topic in recent years because of its flexibility. In this work a close range stereoscopic technique is used to calibrate stereoscopic camera. The camera calibration is estimated the those parameters. It is an indispensable step for medical photogrammetric or image guided applications. The quantitative information should derive from the images. Non linear optimization...
In recent years, 3D TVs and the 3D video contents are widely exploited for many people. Due to these developments, many people will want to shoot the 3D contents with the stereoscopic camera, and share these contents by uploading them to the UCC website. However, some people can experience the visual discomfort and fatigue when they are watching the 3D video. In the manufacturing process of low-price...
In recent years, 3D TVs and the 3D video contents such as movie, commercial film, or drama are widely exploited for many people. Due to these developments, many people will want to make the 3D contents with 3D cameras, and share these contents by uploading them to the UCC website. However, some people can experience the visual discomfort and fatigue when they are watching 3D video contents on the...
This paper presents an experimental study and investigation of errors in 3D reconstruction from views in a canonical stereo camera setup with point correspondences of a grid known apriori. The objective of investigation is to find the estimate of P by Direct Linear Transform (DLT) solution i.e by minimizing the algebraic error (║AP║) subjected to normalizing constraint ║P║=1 and then further minimizing...
The goal in this paper is to detect and remove shadows of moving objects in colour image sequences. The method works by deriving the shadow edges of a 3-band colour image, integrating edge information temporally in the image sequence, and subsequently removing these shadows by a method paralleling reflectance recovery by entropy minimisation. The method incorporates background subtraction information...
In this paper, a novel method for estimating the transformation between an inertial measurement unit (IMU) and a camera together with the intrinsic parameters of the camera is proposed. The method relies on images of reflected feature points in a planar mirror captured by an uncalibrated camera mounted with an IMU. It does not rely on using a fixed calibration pattern in front of the moving camera...
This paper introduces a proof-of-concept telepresence system that offers fully dynamic, real-time 3D scene capture and continuous-viewpoint, head-tracked stereo 3D display without requiring the user to wear any tracking or viewing apparatus. We present a complete software and hardware framework for implementing the system, which is based on an array of commodity Microsoft Kinect™color-plus-depth cameras...
Camera calibration is a key technology in the application of the stereo visual system. On the basis of analyzing the OpenCV camera model and the existing calibration methods of a binocular vision system, a binocular camera calibration algorithm was designed to obtain the internal and external camera parameters. Considering the importance of corner extraction in the camera calibration, a new corner...
Camera calibration based on plane pattern is widely used for its convenience, but current methods to detect patterns and point correspondences are mainly manual or interactive, and the pattern commonly used is a printed chessboard image sticking on plane plate. The paper proposes a novel method to calibrate the camera accurately in a rapid and automatic way. It uses a circle pattern displayed on a...
This paper introduces a proof-of-concept telepresence system that offers fully dynamic, real-time 3D scene capture and continuous-viewpoint, head-tracked stereo 3D display without requiring the user to wear any tracking or viewing apparatus. We present a complete software and hardware framework for implementing the system, which is based on an array of commodity Microsoft Kinect™color-plus-depth cameras...
A 1D object is a segment with several known-distance markers, and calibration methods with 1D objects are more flexible than those with 2D/3D objects. Under the pinhole camera model, it is proved that the calibration with free-moving 1D objects is not possible. For a central catadioptric camera setup, can the camera be calibrated by a 1D object under general motions? In this paper, we prove that a...
Different techniques exist for camera calibration based on photogrammetry or self-calibration. Much work has been done to obtain intrinsic and extrinsic camera parameters and also in data pre - and post-processing techniques. From a practical viewpoint, it is quite difficult to decide which calibration method produces the best results and even whether any data processing is necessary. This paper proposes...
Camera calibration is a necessary step to extract 3D information from 2D images. Since the 1D object is easy to construct and without self-occlusion, the 1D calibration proposed by Zhang has received many attentions. However, the progress in 1D calibration mainly focuses on reducing restrictions on the 1D object's movements. The calibration accuracy still demands improvements. In this paper, the computational...
An improved calibration algorithms have been proposed in this paper. With studying Zhang's calibration algorithm, we found that the distortion model contains only radial distortion, and the mathematical form of distortion model is not applicable. Using this model solving three-dimensional coordinates of the point in image will be calculated with greater error. The paper changed the mathematical form...
Individual plant recognition is a big challenge in the agricultural robotics. Implementation of sensor technologies and algorithms for automatic plant phenotyping are of increasing importance [3]. For an individual plant phenotyping, a multi-camera network is required. The problem of camera calibration is the focus of this research. In this paper, we present a novel extrinsic camera calibration method,...
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