OpenCV实战项目——角度测量

• 数学处理
• 代码
• 结果

# 角度测量
import cv2
import math

path = '1.jpg'  # 读取路径
img = cv2.imread(path)  # 读取图像
pointsList = []  # 储存我们点击的点

# 获取鼠标点函数
def mousePoints(event, x, y, flags, params):  # 鼠标点，xy，标志和参数
    if event == cv2.EVENT_LBUTTONDOWN:  # 按住左键
        size = len(pointsList)
        if size != 0 and size % 3 != 0:
            cv2.line(img, tuple(pointsList[round((size-1)/3)*3]), (x, y), (0, 0, 255), 2)  # 画线（tuple数组转化对象）
        cv2.circle(img, (x, y), 5, (0, 0, 255), cv2.FILLED)  # 画出点击圆
        pointsList.append([x, y])  # 将点添加进入列表

# 求两直线斜率函数
def gradient(pt1,pt2):
    return (pt2[1]-pt1[1])/(pt2[0]-pt1[0])

# 获得角度函数
def getAngle(pointsList):
    pt1, pt2, pt3 = pointsList[-3:]
    m1 = gradient(pt1, pt2)
    m2 = gradient(pt1, pt3)
    angR = math.atan((m2 - m1) / (1 + (m2 * m1)))  # 计算出弧度
    angD = round(math.degrees(angR))  # 转化为角度制

    cv2.putText(img, str(angD), (pt1[0] - 40, pt1[1] - 20), cv2.FONT_HERSHEY_COMPLEX,
                1.5, (0, 0, 255), 2)  # 写上文本

while True:
    if len(pointsList) % 3 == 0 and len(pointsList) != 0:  # 如果列表长度为三的倍数，则才获得角度
        getAngle(pointsList)
    cv2.imshow('image', img)  # 展示图像
    cv2.setMouseCallback('image', mousePoints)
    if cv2.waitKey(1) & 0xFF == ord('q'):  # 按住q进行清除
        pointsList = []
        img = cv2.imread(path)