【Python】【 OpenCV】视频帧和摄像头帧操作 and 窗口显示

 1 import cv2
 2 
 3 # 创建一个视屏捕获对象
 4 videoCapture = cv2.VideoCapture('AVI.avi')
 5 
 6 # 获取视频的属性值，cv2.CAP_PROP_FPS获取视频帧率
 7 fps = videoCapture.get(cv2.CAP_PROP_FPS)
 8 
 9 # cv2.CAP_PROP_FRAME_WIDTH/HEIGHT 返回float类型 获取视频帧的宽高
10 size = int(videoCapture.get(cv2.CAP_PROP_FRAME_WIDTH)), \
11        int(videoCapture.get(cv2.CAP_PROP_FRAME_HEIGHT))
12 
13 '''
14 创建一个写入对象，将帧写入输出的视频
15 cv2.VideoWriter_fourcc()函数指定编码器为 I420
16 fps 和 size 指定输出的帧率和尺寸
17 '''
18 videoWrite = cv2.VideoWriter('Out.avi',
19                              cv2.VideoWriter_fourcc('I', '4', '2', '0'),
20                              fps, size
21                              )
22 
23 '''
24 对捕获到的视频对象进行读取帧，success表示是否成功读取一帧，frame表示当前帧。
25 循环读取写入输出视频。
26 '''
27 success, frame = videoCapture.read()
28 while success:
29        videoWrite.write(frame)
30        success, frame = videoCapture.read()

 1 import cv2
 2 
 3 cameraCapture = cv2.VideoCapture(0)
 4 
 5 fps = 30
 6 
 7 size = int(cameraCapture.get(cv2.CAP_PROP_FRAME_WIDTH)), \
 8         int(cameraCapture.get(cv2.CAP_PROP_FRAME_HEIGHT))
 9 
10 videoWriter = cv2.VideoWriter(
11     'OutVideo_GRAB.avi',
12     cv2.VideoWriter_fourcc('I', '4', '2', '0'),
13     fps,
14     size
15 )
16 
17 success, frame = cameraCapture.read()
18 
19 numFramesRemaining = 10 * fps
20 while success and numFramesRemaining > 0:
21     videoWriter.write(frame)
22     success, frame = cameraCapture.read()
23     numFramesRemaining -= 1

1 import cv2
2 
3 img = cv2.imread('CopyPic.png')
4 cv2.imshow('', img)
5 cv2.waitKey()
6 cv2.destroyAllWindows()

 1 import cv2
 2 
 3 # 检测窗口是否被点击
 4 clicked = False
 5 
 6 
 7 # 定义鼠标事件处理函数
 8 def onMouse(event: int, x, y, flags, param):
 9     global clicked
10     if event == cv2.EVENT_LBUTTONUP:
11         clicked = True
12 
13 
14 # 创建一个视频对象
15 cameraCapture = cv2.VideoCapture(0)
16 # 定义窗口命
17 cv2.namedWindow('Camera')
18 # 将鼠标回调函数，将鼠标事件处理函数和窗口关联起来
19 cv2.setMouseCallback('Camera', onMouse)
20 
21 print('Showing camera feed. Click window or press any key to stop.')
22 # 获取当前时间的摄像头帧
23 success, frame = cameraCapture.read()
24 
25 # 循环获取当前时间的摄像头帧，当按下任意按键 or 点击鼠标时则停止显示
26 while success and cv2.waitKey(1) == -1 and not clicked:
27     cv2.imshow('Camera', frame)
28     success, frame = cameraCapture.read()
29 
30 # 关闭窗口
31 cv2.destroyAllWindows()
32 
33 # 释放摄像头资源
34 cameraCapture.release()

 1 import cv2
 2 
 3 for item in range(10):
 4     # 创建一个object
 5     camera = cv2.VideoCapture(item)
 6 
 7     # 查询此摄像头是否能打开，如果不能则跳过，并输出一条 Error Message
 8     if not camera.isOpened():
 9         print(f"Can\'t open camera {item}")
10         continue
11 
12     # 读取摄像头帧率
13     while True:
14         success, frame = camera.read()
15         # 当摄像头帧读取失败则跳过
16         if not success:
17             break
18 
19         cv2.imshow(f'Camera device number: {item}', frame)
20 
21         # 等待1毫秒，检查用户是否有键盘输入‘q’
22         if cv2.waitKey(1) == ord('q'):
23             break
24 
25     camera.release()
26     cv2.destroyAllWindows()