import cv2 as cv
cap = cv.VideoCapture(0)
if not cap.isOpened():
print("Cannot open camera")
exit()
while True:
ret, frame = cap.read()
if not ret:
print("Can't receive frame, Exiting ...")
break
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
cv.imshow('frame', gray)
if cv.waitKey(1) == ord('q'):
break
cap.release()
cv.destroyAllWindows()
import cv2 as cv
cap = cv.VideoCapture(0)
if not cap.isOpened():
print("Cannot open camera")
exit()
print("默认值:")
print(cap.get(cv.CAP_PROP_FRAME_WIDTH))
print(cap.get(cv.CAP_PROP_FRAME_HEIGHT))
cap.set(cv.CAP_PROP_FRAME_WIDTH,160)
cap.set(cv.CAP_PROP_FRAME_HEIGHT,120)
print("修改后的值:")
print(cap.get(cv.CAP_PROP_FRAME_WIDTH))
print(cap.get(cv.CAP_PROP_FRAME_HEIGHT))
while True:
ret, frame = cap.read()
if not ret:
print("Can't receive frame, Exiting ...")
break
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
cv.imshow('frame', gray)
if cv.waitKey(1) == ord('q'):
break
cap.release()
cv.destroyAllWindows()
运行结果为:
默认值:
640.0
480.0
修改后的值:
160.0
120.0
从文件播放视频 只需将cv.VideoCapture()参数改为视频文件路径即可
import cv2 as cv
cap = cv.VideoCapture('C:\\work_test\\vedio.mp4')
if not cap.isOpened():
print("Cannot open file")
exit()
while True:
ret, frame = cap.read()
if not ret:
print("Can't receive frame, Exiting ...")
break
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
cv.imshow('frame', gray)
if cv.waitKey(25) == ord('q'):
break
cap.release()
cv.destroyAllWindows()