img_test.py

# import cv2

# if __name__ == "__main__":
#     img = cv2.imread("D://YanDengfeng//SRT//ROS//UR5e_kinematics//image2.png")
#     img = cv2.resize(img, dsize=None, fx=0.5, fy=0.5)
#     gray_blur = cv2.medianBlur(img, 9)
#     edge_img = cv2.Canny(gray_blur, 100, 200)
#     cv2.imshow("image", img)
#     cv2.imshow("edges", edge_img)
#     cv2.waitKey(0)
#     cv2.destroyAllWindows()

# coding=utf-8
# 使用OpenCV视频中提取帧图片并保存(cv2.VideoCapture)
import os
import cv2
import shutil
import time

# 全局变量
VIDEO_PATH = 'CPS.mp4'  # 视频地址
EXTRACT_FOLDER = 'cps'  # 存放帧图片的位置
EXTRACT_FREQUENCY = 10  # 帧提取频率


# 主操作
def extract_frames(video_path, dst_folder, index):
    # 实例化视频对象
    video = cv2.VideoCapture(video_path)
    frame_count = 0

    # 循环遍历视频中的所有帧
    while True:
        # 逐帧读取
        _, frame = video.read()
        if frame is None:
            break
        frame = cv2.resize(frame, dsize=None,fx=0.5,fy=0.5)
        gray_blur = cv2.medianBlur(frame, 9)
        edge_img = cv2.Canny(gray_blur, 100, 200)
        # 按照设置的频率保存图片
        if frame_count % EXTRACT_FREQUENCY == 0:
            # 设置保存文件名
            save_path = "{}/{:>03d}.jpg".format(dst_folder, index)
            # 保存图片
            cv2.imwrite(save_path, edge_img)
            index += 1  # 保存图片数＋1
        frame_count += 1  # 读取视频帧数＋1

    # 视频总帧数
    print(f'the number of frames: {frame_count}')
    # 打印出所提取图片的总数
    print("Totally save {:d} imgs".format(index - 1))

    # 计算FPS 方法一 get()
    (major_ver, minor_ver, subminor_ver) = (cv2.__version__).split('.')  # Find OpenCV version
    # (major_ver, minor_ver, subminor_ver) = (4, 5, 4)
    if int(major_ver) < 3:
        fps = video.get(cv2.cv.CV_CAP_PROP_FPS)  # 获取当前版本opencv的FPS
        print("Frames per second using video.get(cv2.cv.CV_CAP_PROP_FPS): {0}".format(fps))
    else:
        fps = video.get(cv2.CAP_PROP_FPS)  # 获取当前版本opencv的FPS
        print("Frames per second using video.get(cv2.CAP_PROP_FPS) : {0}".format(fps))

    # 计算FPS 方法二 手动计算 总帧数 / 总时间
    # new_vid = cv2.VideoCapture(video_path)
    # start = time.time()  # 开始时间
    # c = 0
    # while True:
    #     _, frames = new_vid.read()
    #     if frames is None:
    #         break
    #     c += 1
    # end = time.time()  # 结束时间
    # fps2 = c / (end - start)  # 总帧数 / 总时间
    # print(f'frames:{c}')
    # print(f'seconds:{end - start}')
    # print("Frames per second using frames / seconds : {0}".format(fps2))
    # new_vid.release()

    # 最后释放掉实例化的视频
    video.release()


def main():
    # 递归删除之前存放帧图片的文件夹，并新建一个
    try:
        shutil.rmtree(EXTRACT_FOLDER)
    except OSError:
        pass
    os.mkdir(EXTRACT_FOLDER)
    # 抽取帧图片，并保存到指定路径
    extract_frames(VIDEO_PATH, EXTRACT_FOLDER, 1)


if __name__ == '__main__':
    main()