1.读取图片
import cv2 # LOAD AN IMAGE USING 'IMREAD' img = cv2.imread("Resources/lena.png") # DISPLAY cv2.imshow("Lena Soderberg", img) cv2.waitKey(0)2.读取视频
import cv2 frameWidth = 640 frameHeight = 480 cap = cv2.VideoCapture("Resources/test_video.mp4") while True: success, img = cap.read() img = cv2.resize(img, (frameWidth, frameHeight)) cv2.imshow("Result", img) if cv2.waitKey(1) & 0xFF == ord('q'): break3.调用摄像头
import cv2 frameWidth = 640 frameHeight = 480 #选用摄像头 cap = cv2.VideoCapture(0) #设置参数 cap.set(3, frameWidth) cap.set(4, frameHeight) cap.set(10, 150) while True: success, img = cap.read() cv2.imshow("Result", img) if cv2.waitKey(1) & 0xFF == ord('q'): breakcap.set为设置参数，参数编号的对应关系怎么样，请看下面列表。
0. CV_CAP_PROP_POS_MSEC Current position of the video file in milliseconds. 1. CV_CAP_PROP_POS_FRAMES 0-based index of the frame to be decoded/captured next. 2. CV_CAP_PROP_POS_AVI_RATIO Relative position of the video file 3. CV_CAP_PROP_FRAME_WIDTH Width of the frames in the video stream. 4. CV_CAP_PROP_FRAME_HEIGHT Height of the frames in the video stream. 5. CV_CAP_PROP_FPS Frame rate. 6. CV_CAP_PROP_FOURCC 4-character code of codec. 7. CV_CAP_PROP_FRAME_COUNT Number of frames in the video file. 8. CV_CAP_PROP_FORMAT Format of the Mat objects returned by retrieve() . 9. CV_CAP_PROP_MODE Backend-specific value indicating the current capture mode. 10. CV_CAP_PROP_BRIGHTNESS Brightness of the image (only for cameras). 11. CV_CAP_PROP_CONTRAST Contrast of the image (only for cameras). 12. CV_CAP_PROP_SATURATION Saturation of the image (only for cameras). 13. CV_CAP_PROP_HUE Hue of the image (only for cameras). 14. CV_CAP_PROP_GAIN Gain of the image (only for cameras). 15. CV_CAP_PROP_EXPOSURE Exposure (only for cameras). 16. CV_CAP_PROP_CONVERT_RGB Boolean flags indicating whether images should be converted to RGB. 17. CV_CAP_PROP_WHITE_BALANCE Currently unsupported 18. CV_CAP_PROP_RECTIFICATION Rectification flag for stereo cameras (note: only supported by DC1394 v 2.x backend currently)