写一段利用python语言，读取悬臂梁振动冲击视频，利用圆心标靶检测算法、Gunner Farneback算法计提取测点的位移并绘制每个测点的位移时程曲线的完整算法

好的，以下是利用 Python 读取悬臂梁振动冲击视频，利用圆心标靶检测算法、Gunner Farneback算法提取测点的位移并绘制每个测点的位移时程曲线的完整算法：

1. 导入所需的库和模块：

import cv2
import numpy as np
import matplotlib.pyplot as plt

2. 读取视频文件：

cap = cv2.VideoCapture('video.mp4')

3. 定义圆心标靶检测算法，用于检测每个测点的位置：

def detect_circles(frame):
    # 灰度化
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    # 中值滤波
    gray = cv2.medianBlur(gray, 5)
    # 圆心标靶检测
    circles = cv2.HoughCircles(gray, cv2.HOUGH_GRADIENT, 1, 20, param1=50, param2=30, minRadius=0, maxRadius=0)
    if circles is not None:
        # 转换为整数
        circles = np.round(circles[0, :]).astype("int")
        return circles
    else:
        return None

4. 定义 Ganner Farneback 算法，用于提取测点的位移：

def calculate_optical_flow(prev_frame, cur_frame, prev_points):
    # 灰度化
    prev_gray = cv2.cvtColor(prev_frame, cv2.COLOR_BGR2GRAY)
    cur_gray = cv2.cvtColor(cur_frame, cv2.COLOR_BGR2GRAY)
    # 计算光流
    cur_points, status, error = cv2.calcOpticalFlowPyrLK(prev_gray, cur_gray, prev_points, None, winSize=(15, 15), maxLevel=2, criteria=(cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 0.03))
    # 筛选出良好的点
    good_new = cur_points[status == 1]
    good_old = prev_points[status == 1]
    # 计算位移
    displacement = good_new - good_old
    return good_new, displacement

5. 定义绘制位移时程曲线的函数：

def plot_displacement(displacement):
    # 绘制位移时程曲线
    x = np.arange(0, len(displacement))
    y = displacement[:, 1]
    plt.plot(x, y)
    plt.show()

6. 进入主循环，逐帧处理：

# 读取第一帧
ret, prev_frame = cap.read()
prev_circles = detect_circles(prev_frame)
prev_points = np.array([[x, y] for x, y, r in prev_circles])
# 逐帧处理
while True:
    # 读取当前帧
    ret, cur_frame = cap.read()
    if not ret:
        break
    cur_circles = detect_circles(cur_frame)
    if cur_circles is not None:
        cur_points = np.array([[x, y] for x, y, r in cur_circles])
        # 计算位移
        cur_points, displacement = calculate_optical_flow(prev_frame, cur_frame, prev_points)
        # 绘制位移时程曲线
        plot_displacement(displacement)
        # 更新上一帧的信息
        prev_frame = cur_frame.copy()
        prev_points = cur_points.copy()

这样就完成了读取悬臂梁振动冲击视频，利用圆心标靶检测算法、Gunner Farneback算法提取测点的位移并绘制每个测点的位移时程曲线的完整算法。