基于变步长的旋转投影变换法

车牌识别系统是智能交通的重要组成部分,在日益凸显的道路交通问题上发挥着举足轻重的作用。车牌的倾斜校正是字符分割和字符识别正确与否的一个重要因素。旋转投影变换法能够很好地解决车牌倾斜的问题,但是对一个特定范围内的所有角度进行此变换,增加了计算所需要的时间。为了降低算法所需要的时间,文中结合旋转投影变换法,在此基础上根据旋转后投影的直方图必有一个峰值的特点,提出了变步长的旋转投影变换方法。仿真表明,在相同的情况下,改进的算法的运行时间得到改善。

用投影变换法图解力矩

论述了投影变换法在静力学中的一个应用即如何应用投影变换法来图解力矩。投影变换法能够使一般位置的直线经过若干次变换在投影图中反映实际的长度或距离,使一些应用数学理论解决的问题变得简单明了。该方法简单易行,实用性强,在工程实际中有一定的应用价值。

用投影变换法计算溜管角度和长度

溜管是一种利用物料自身重力进行降运的设备。在粮食加工厂的设计安装过程中,经常涉及到溜管的角度和实长这一计算问题。如果溜管角度过小——物料输送困难,甚至造成管路堵塞,迫使停车;

GIS中多源空间数据集成方法研究

针对GIS中存在的空间数据多源化问题,分析了空间数据多源化产生的原因和表现形式,并从空间数据应用角度出发,详细阐述了数据格式转换法、坐标系转换与投影变换法、几何纠正法等三种常用空间数据集成方法的基本原理。

Flexible Calibration Method for 3D Laser Scanner System

In this paper, a flexible high-precision calibration method suitable for industrial field was proposed. The complexity of the coordinate transformation was simplified by choosing the camera coordinate system as the unified reference coordinate system. A flexible planar calibration pattern was introduced to the calibration process, which can be arbitrarily placed and from which the known feature points can be extracted to construct other unknown feature points. With the known intrinsic parameters, the laser projector plane equation was fitted by the multi-noncollinear points, which were acquired through the principle of triangulation and the projective invariance of cross ratio. With this method, the strict alignment and multiple times of coordinate transformation can be avoided. Experimental results showed that the arithmetic mean of the root mean square(RMS) error of distance was 0.000 7 mm.