Narrow Results

A method for arbitrary surface reconstruction from 3D large scattered points is proposed in this paper. According to the properties of 3D points, e.g. the non-uniform distribution and unknown topology, an implicit surface model is adopted based on radial basis functions network. And because of the property of locality of radial basis function, the method is fast and robust in surface reconstruction. Furthermore, an adapted K-Means algorithm is used to reduce reconstruction centers. For features completeness, two effective methods are introduced to extract the feature points before the adapted K-Means algorithm. Experiment results show that the presented approach is a good solution for reconstruction from 3D large scattered points.

In recent years, human support robots have been receiving attention. Especially, object recognition task is important in case that people request the robots to transport and rearrange an object. We consider that there are four necessary properties to recognize in domestic environment as follows. (1) Robustness against occlusion. (2) Fast recognition. (3) Pose estimation with high accuracy. (4) Coping with erroneous correspondences. As conventional object recognition methods using 3-dimensional information, there are model-based recognition methods such as the SHOT and the Spin Image. The SHOT and the Spin Image do not satisfy all four properties for the robots. Therefore, to satisfy the four properties of recognition, we propose a 3-dimensional object recognition method by using relationship of distances and angles in feature points. As per our approach, the proposed method achieves to solve problems of conventional methods by using not only the feature points but also relationship between feature points. To achieve this purpose, firstly, the proposed method uses a curvature as a feature in a local region. Secondly, the proposed method uses points having high curvature as feature points. Finally, the proposed method generates a list by listing relationship of distances and angles between feature points and matches lists.

The accuracy of feature-based vision algorithms, including the self-calibration of binocular camera extrinsic parameters used in autonomous driving environment perception techniques relies heavily on the quality of the features extracted from the images. This study investigates the influence of the depth distance between objects and the camera, the feature points in different object regions, and the feature points in dynamic object regions on the self-calibration of binocular camera extrinsic parameters. To achieve this, the study first filters out different types of objects in the image through semantic segmentation. Then, it identifies the areas of dynamic objects and extracts the feature points in the static object region for the self-calibration of binocular camera extrinsic parameters. By calculating the baseline error of the binocular camera and the row alignment error of the matching feature points, this study evaluates the influence of feature points in dynamic object regions, feature points in different object regions, and feature points at different distances on the self-calibration algorithm. The experimental results demonstrate that feature points at static objects close to the camera are beneficial for the self-calibration of extrinsic parameters of binocular camera.

For given rows of data points, a new approach of B-spline surface reconstruction is presented based on feature points of sectional curves. Firstly, a new knot placement for B-spline curve reconstruction is proposed, obtaining initial B-spline curves approximating to the data points. The local curvature maximum points are recognized and extracted automatically by curvature information. The local curvature maximum points and two end points are viewed as seed points of the feature points. We construct B-spline curves approximating to the seed points, refining the feature points and updating the knot vector by B-spline curve segment complexity. The largest number of the knot vectors is regarded as candidate vectors, the common knot vectors for B-spline surface lofting can be gained by the knot tolerance and the knot insertion. Finally, the B-spine surface approximating to the data points can be accomplished by surface lofting. Compared to other B-spline surface reconstruction, our approach can reduce control points and improve efficiency of B-spline surface reconstruction.