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1.
吴健康  高枫 《机器人》1990,12(5):35-39
三维物体的表达和识别是图象理解和场景分析的核心问题,三维模型在三维物体的识别和场景分析中具有十分重要的作用.三维模型应该是以物体为中心的,能够提供该场景的所有有用信息.物体的大小,形状及朝向应均可从该模型中提取得到.本文提出了一种新的三维物体模型——广义的以物体为中心的行程编码.它包括物体的GORC物理数据结构,详细的形状描述和抽象描述.物体的高层次的表达可以通过以GORC编码的物理数据直接提取得到.三维的GORC是二维的以物体为中心的行程编码在三维上的推广,它兼有物体的体积表达和表面表达的优点.三维物体的GORC模型可以很容易地由其深度信息构造得出,基于GORC的投影运算,图象代数运算以及特征提取均可非常有效地实现.  相似文献   

2.
基于神经网络的三维物体姿态测定   总被引:2,自引:0,他引:2  
王建刚  王寻羽 《机器人》1996,18(2):83-90
利用单幅图象中物体的三条边与模型中的三条对应边,可求出三维物体姿态,但解不唯一,通过将这些可能姿态所产生的图象与实际图象匹配,可求出唯一正确姿态。二维图象特征对应问题是个NP完全问题,存在组合爆炸的困难,为此,我们把特征对应问题看作一个组合优化问题,利用Hopfield网络成功解决这一组合优化问题,该算法通用性强,而且适合于并行实现,文中给出了在VI-COM图象处理系统上对人造图象和实际图象进行的  相似文献   

3.
模型的表示和构建是基于距离图象三维物体识别技术中的关键模块之一.针对已有方法 存在的若干问题,提出一个新的综合多个视角距离图象的三维物体模型表示策略和增量式的 模型习得算法,并将该模型表示用于三维物体识别中.实验结果验证了算法的有效性.  相似文献   

4.
在三维点云识别过程中,由于点云姿态不同,比较点的特征时,要将空间姿态变换计算在内,旧的空间姿态算法复杂度高,计算量大。针对上述问题,提出一种相似物体的姿态矫正算法,通过在两个相似物体要进行识别的位置上选择不共线的三组对应点,经过空间变换与旋转,将相似部位的姿态统一,为物体识别做基础。通过使用汽车点云模型进行矫正,验证了该算法的可行性和正确性。  相似文献   

5.
一种基于阵列式触觉传感器的主动触觉搜索方法及仿真   总被引:2,自引:1,他引:1  
张庆  蒋洪明 《机器人》1994,16(2):82-86
本文在一种二指节手指模型的基础上,提出了一种新的主动触觉搜索策略和方法,综合利用阵列式触觉传感铭的输出图象来不断改变机械手的姿态,从而依次有序地搜索到三维物体的特征点,并据此生成物体的三维图形。此外还讨论了上述方法的计算机仿真实现。  相似文献   

6.
利用稀疏距离图象与灰度图象相结合,通过射影变换可使灰度图象特征有条件地获取距离信息,这称为 基于射影变换的距离信息扩展原理。利用这些距离信息可计算物体表面平面图形的欧氏空间不变量并对景物中的 物体产生假设。由于初始假设建立在可靠的基础上,并使用了带反馈的混合控制策略,使这种基于模型的物体识别 定位技术具有实用的前景。此文讨论了整个方法的原理及其实施方案,并实验验证了原理的正确性与有效性。  相似文献   

7.
基于特征轮廓的灰度图像定位三维物体方法   总被引:1,自引:0,他引:1  
讨论了一种基于特征轮廓的从三维灰度图像确定三维物体位置和姿态的方法,该方法首先建立物体的三维网页模型,检测模型上的特征点,并建立该物体的特征轮廓模型,然后检测输入图像中物体上的特征点,形成特征轮廓,并与特征轮廓模型相匹配,就可得到该物体在三维空间中的姿态;最后使用最小二乘法对物体进行精确定位,实验证明,该方法在物体遮挡情况下不是很严重时,可以快速精确地从灰度图像定位三维物体。  相似文献   

8.
基于方面图技术的三维运动目标识别   总被引:1,自引:0,他引:1       下载免费PDF全文
三维目标在不同的视点下呈现不同的姿态 ,所得的二维视图也不尽相同 ,因此三维目标识别是一个较为复杂的问题 .为此提出了通过图象序列和图象序列之间的转移关系 ,根据胜者为王的原则来识别三维目标的方法 .该方法采用极指数栅格技术和傅立叶变换相结合得到目标的轮廓不变量 ;用神经网络结合方面图技术 ,通过识别运动目标图象序列来识别三维运动目标 ,实现了一个目标识别系统 .实验结果证明 ,此方法可以有效地用于三维运动目标的识别  相似文献   

9.
魏永超  郑涛 《计算机应用》2010,30(10):2718-2722
提出一种新的基于局部描述符的点云物体识别算法。算法根据点云的位置信息提取出邻域以及曲率信息,进而得到形状索引信息。根据形状索引提取到特征点,在每个特征点根据样条拟合原理得到测地距离和矢量夹角分割曲面得到曲面片集。每个曲面片的等距测地线构成了曲面片指纹,通过矢量和半径的变化描述,可以把每个模型物体得到的曲面片集描述存入数据库。对于给定的一个物体,根据上面步骤同样得到其曲面片集描述,通过和数据库中模型物体曲面片集的比对,得到初始识别结果。对每对初始识别结果进行对应滤波后,通过最近点迭代方法得到最终的识别结果。最后通过具体的实验说明了算法的有效性和高效性。  相似文献   

10.
基于CAD模型的多传感器视觉系统(CAD Model Based Multiple Sensor Vision System)CMMS是面向装配机器人的视觉导引的视觉系统。CMMS以CAD三维建模系统为基础自动生成视觉系统模型以及识别定位策略,装配机器人的视觉引导除了要求实时性以外,主要的特点是需要满足从空间路径规划到装配操作的多层次、多分辨率的导引要求和定位精度,为此CMMS采用分层的多传感器信息处理结构:第一层是多视角图象投影三维信息获取和物体识别;第二层是基于预测的物体识别定位;第三层是结构光三维信息获取和处理,各层的信息以逐层导引的方式融合。CMMS系统硬件由SUN3工作站、?BOX图象系统、PUMA—560机械手,以及全局和移动式视觉系统组成。现在系统已初步建成。  相似文献   

11.
12.
Designers and creative artists use computer graphics and image processing effects on stall photographs in application areas such as advertising entertainment broadcasting and the arts Most of the effects available in research arid commercial work are two-dimensional in nature, for example image processing filters [blur, edge enhancement) and creative effects (tilings, reflections) There is almost no usage of information taken from the 3-D world in which the objects appearing an the image are located. In this paper we present a novel method for creating 3-D effects on photographs or in general on any image created by rendering a 3-D world The artist interacts with the image using a set of intuitive direct manipulation interface objects These objects let the user define a 3-D model, display at, and manipulate it in a 3-D space which is correlated with that of the input image. The generated model can be an arbitrarily complex 3-D polyhedron Any texture, including texture taken from the input photograph, can be mapped into any of its faces arid used for special effects We discuss and show examples for effects such as copy and paste, motion blur, model editing and deformations lighting effects, and shadows.  相似文献   

13.
14.
We propose a technique for 3-D modeling of objects in remote dynamic situations employing mobile stereocameras. Since the proposed technique allows independent movement of the cameras employed, 3-D modeling under various environments, such as remote places, can be realized. Our technique has an advantage over others in that camera calibration is not prerequisite to the 3-D modeling before taking images. A 3-D modeling system is described that captures images of remote objects, transfers the images by analog airwaves, and recovers the 3-D shape of the object from the images. It is expected that this technique will improve the efficiency of image information transfer. In the experiment performed, a human walking in a remote place was modeled successfully in 3-D in a laboratory by image transfer. This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January 23–25, 2006  相似文献   

15.
Spence I 《Human factors》2004,46(4):738-747
Information displays commonly use 2-D and 3-D objects even though the numbers represented are 1-D. This practice may be problematic because the psychophysical relation between perceived and physical magnitudes is generally nonlinear for areas and volumes. Nonetheless, this research shows that apparent 2-D and 3-D objects can produce linear psychophysical functions if only one dimension shows variation. Processing time increases with the number of dimensions in the objects that show variation, not with the apparent dimensionality. Indeed, when only one dimension showed variation, apparent 3-D objects were judged more quickly than were apparent 2-D or 1-D objects. These results present a challenge for computational models of size perception and have implications for the design of information displays. Actual or potential applications of this research include the design and use of statistical graphs and information displays; objects that display variation in more than one dimension should not be used to represent single (1-D) numerical variables if they are to be judged accurately and rapidly.  相似文献   

16.
In this paper, we present an image understanding system using fuzzy sets and fuzzy measures. This system is based on a symbolic object-oriented image interpretation system. We apply a simple, powerful three-dimensional (3-D) recursive filter to tracking moving objects in a dynamic image sequence. This filter has a time-varying 3-D frequency-planar passband that is adapted in a feedback system to automatically track moving objects. However, as objects in the image sequence are not well-defined and are engaged in dynamic activities, their shapes and trajectories in most cases can be described only vaguely. In order to handle these uncertainties, we use fuzzy measures to capture subtle variations and manage the uncertainties involved. This enables us to develop an image understanding system that produces a very natural output. We demonstrate the effectiveness of our system with complex real traffic scenes.  相似文献   

17.
The recovery of 3-D shape information (depth) using stereo vision analysis is one of the major areas in computer vision and has given rise to a great deal of literature in the recent past. The widely known stereo vision methods are the passive stereo vision approaches that use two cameras. Obtaining 3-D information involves the identification of the corresponding 2-D points between left and right images. Most existing methods tackle this matching task from singular points, i.e. finding points in both image planes with more or less the same neighborhood characteristics. One key problem we have to solve is that we are on the first instance unable to know a priori whether a point in the first image has a correspondence or not due to surface occlusion or simply because it has been projected out of the scope of the second camera. This makes the matching process very difficult and imposes a need of an a posteriori stage to remove false matching.In this paper we are concerned with the active stereo vision systems which offer an alternative to the passive stereo vision systems. In our system, a light projector that illuminates objects to be analyzed by a pyramid-shaped laser beam replaces one of the two cameras. The projections of laser rays on the objects are detected as spots in the image. In this particular case, only one image needs to be treated, and the stereo matching problem boils down to associating the laser rays and their corresponding real spots in the 2-D image. We have expressed this problem as a minimization of a global function that we propose to perform using Genetic Algorithms (GAs). We have implemented two different algorithms: in the first, GAs are performed after a deterministic search. In the second, data is partitioned into clusters and GAs are independently applied in each cluster. In our second contribution in this paper, we have described an efficient system calibration method. Experimental results are presented to illustrate the feasibility of our approach. The proposed method yields high accuracy 3-D reconstruction even for complex objects. We conclude that GAs can effectively be applied to this matching problem.  相似文献   

18.
杨杰  陈健 《计算机工程》2001,27(4):174-176
介绍了采用映射参数模型进行分层结构型分割的方法,并采用Matlab语言对该算法的部分内容进行了验证。该方法利用时空图象亮度梯度和运动信息来估算三维运动和结构参数,分割区域用运动和位置参数定义,这些参数被称为映射参数,通过变化检测,映射参数估算,运动区域和背景检测来实现运动分割。  相似文献   

19.
20.
In this article, three models in two different spaces are compared for use with an image processing system working in real time. A static geometric model of a robot work-cell is held in computer memory as several solid polyhedra. This model is updated as new objects enter or leave the workplace. Similar 2-D slices in joint space, spheres, and simple polyhedra are used to model these objects. The three models are compared for their ability to be updated with new information and for the efficiency of the whole system in accessing data concerning new objects. The system supplies data to a “Path Planner.” The path planner contains a geometric model of the static environment and a robot. The robot machinery structure is modeled as connected cylinders and spheres and the range of motion is quantized. © 1995 John Wiley & Sons, Inc.  相似文献   

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