python-3.x - 使用 OpenCv Python 以全高清大小保存图像

Question

当我尝试使用 cv2.imwrite() 方法保存图像时，它保存了一个 640x480 像素大小的文件。我的网络摄像头是全高清(1920×1080 像素)。如何以这种全高清尺寸保存图片。

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()

    # Our operations on the frame come here
    #gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    # Display the resulting frame
    cv2.imshow('frame', frame)
    cv2.imwrite('a.jpg',frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

Answer 1

import numpy as np
import cv2

cap = cv2.VideoCapture(0)
cap.set(3, 1920)
cap.set(4, 1080)
cap.set(6, cv2.VideoWriter.fourcc('M', 'J', 'P', 'G'))

while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()

    # Our operations on the frame come here
    #gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    # Display the resulting frame
    cv2.imshow('frame', frame)
    cv2.imwrite('a.jpg',frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()