圆形识别方案
识别流程
- 判断是否为封闭图形；
- 根据圆的方程，取输入点集中的1/6、3/6、5/6处的三个点，求得圆的方程，获取圆心及半径；
- 取点集中的部分点，计算点到圆心的距离与半径的比例，与设定的阈值比较，得出结果。~~~~
实现
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public static bool IsCircle(List<Point> points, out Point center, out double radius){ int len = points.Count; center = new Point(); radius = 0; // 判断是否为封闭图形 if (!IsClosedFigure(points)) return false; int judgePointNum = len * 50 / 100; if (len < judgePointNum) return false; // 取链表上三个点作为判断圆的根据 Point p1 = points[len / 6]; Point p2 = points[len / 2]; Point p3 = points[len * 5 / 6]; if ((Math.Abs(p1.X - p2.X) < 100 && Math.Abs(p1.Y - p2.Y) < 100) || (Math.Abs(p1.X - p3.X) < 100 && Math.Abs(p1.Y - p3.Y) < 100) || (Math.Abs(p2.X - p3.X) < 100 && Math.Abs(p2.Y - p3.Y) < 100)) return false; // 三个点确定圆的方程，获取圆心坐标及半径 GetCircle(p1, p2, p3, out center, out radius); // 获取圆上平均分部的多个点，判断其到圆心的距离与半径之差是否在精度内 for (int i = 0; i < judgePointNum; ++i) { // 获取圆上点 Point p = points[len * i / judgePointNum]; double deviation = Math.Abs(GetDistance(center, p) - radius); // 点在圆上的偏移量与半径的比值若大于固定值，则不为圆 if (deviation/radius > MaxRatio) return false; } return true;} |
直线识别方案
步骤
1.使用最小二乘法回归直线：
2.得到直线方程y=kx+b后，计算所有点到直线的距离，若在阈值范围内，认为是直线。
实现
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/// <summary>/// 最小二乘法求回归直线方程/// </summary>/// <param name="points">输入数据</param>/// <param name="k">直线斜率</param>/// <param name="b">直线截距</param>/// <param name="type">直线类型 1：水平线 2：垂直线 3：一般直线</param>/// <returns></returns>public static bool IsLine(List<Point> points, out double k, out double b, out int type){ k = 0; b = 0; type = 0; if (points.Count < 2) return false; double averageX = 0, averageY = 0, n = 0; n = points.Count; foreach (Point p in points) { averageX += p.X; averageY += p.Y; } averageX /= n; averageY /= n; double numerator = 0, denominator = 0; foreach (Point p in points) { numerator += (p.X - averageX) * (p.Y - averageY); denominator += (p.X - averageX) * (p.X - averageX); } if (numerator == 0) //平行于X轴为水平线，返回纵坐标平均值 { b = averageY; type = 1; } else if (denominator == 0)//平行于Y轴为垂直线，返回横坐标平均值 { b = averageX; type = 2; } else { type = 3; } k = numerator / denominator; b = averageY - k * averageX; foreach (Point p in points) { dis = GetPoint2LineDistance(p, k, b, type); if (dis > MAX_POINT_LINE_DIS) return false; //点到拟合直线距离过大 } return true;}/// <summary>/// 计算点到直线的距离/// </summary>/// <param name="p">待计算点</param>/// <param name="k">直线斜率</param>/// <param name="b">直线截距</param>/// <param name="type">直线类型 1：水平线 2：垂直线 3：一般直线</param>/// <returns>距离</returns>private static double GetPoint2LineDistance(Point p, double k, double b, int type){ if (type == 1) { return Math.Abs(p.Y - b); } else if (type == 2) { return Math.Abs(p.X - b); } else { double numerator = 0, denominator = 0; numerator = Math.Abs(k * p.X - p.Y + b); denominator = Math.Sqrt(k * k + 1); return numerator / denominator; }} |
以上就是c# 圆形识别方案和直线识别方案的实现示例的详细内容，更多关于c# 圆形识别方案和直线识别方案的资料请关注服务器之家其它相关文章！
原文链接：https://www.cnblogs.com/louzixl/p/14381179.html
