OpenCV稠密光流法可直接运行的例程（python）

# dense_optical_flow.py
import cv2
import numpy as np
import argparse

def dense_optical_flow(method, video_path, params=[], to_gray=False):
    # 读取视频
    cap = cv2.VideoCapture(video_path)
    # 读取第一帧
    ret, old_frame = cap.read()

    # 创建HSV并使Value为常量
    hsv = np.zeros_like(old_frame)
    hsv[..., 1] = 255

    # 精确方法的预处理
    if to_gray:
        old_frame = cv2.cvtColor(old_frame, cv2.COLOR_BGR2GRAY)

    while True:
        # 读取下一帧
        ret, new_frame = cap.read()
        frame_copy = new_frame
        if not ret:
            break
        # 精确方法的预处理
        if to_gray:
            new_frame = cv2.cvtColor(new_frame, cv2.COLOR_BGR2GRAY)
        # 计算光流
        flow = method(old_frame, new_frame, None, *params)

        # 编码:将算法的输出转换为极坐标
        mag, ang = cv2.cartToPolar(flow[..., 0], flow[..., 1])
        # 使用色相和饱和度来编码光流
        hsv[..., 0] = ang * 180 / np.pi / 2
        hsv[..., 2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_MINMAX)