python - 按下按键时保存图像 Python/Opencv

Question

我试图在按下某个键时保存来自网络摄像头的图像，但无法正常工作。在这里我附上我的代码:

import cv

cv.NamedWindow("w1", cv.CV_WINDOW_AUTOSIZE)
camera_index = 0
capture = cv.CaptureFromCAM(camera_index)
i=0

def repeat():
 global capture 
 global camera_index
 frame = cv.QueryFrame(capture)
 cv.ShowImage("w1", frame)
 c = cv.WaitKey(25)
 if(c=="n"): 
  cv.SaveImage("f"+str(i)+".jpg",frame) 
  i=i+1
while True:
    repeat()

Answer 1

cv.WaitKey() 不返回 key ，但在超时时给出 -1。

解决方法:

import cv

cv.NamedWindow("w1", cv.CV_WINDOW_AUTOSIZE)
camera_index = 0
capture = cv.CaptureFromCAM(camera_index)
i=0

def repeat():
 global capture 
 global camera_index
 frame = cv.QueryFrame(capture)
 cv.ShowImage("w1", frame)
 c = cv.WaitKey(25)
 if (c != -1): 
  cv.SaveImage("f"+str(i)+".jpg",frame) 
  i=i+1
while True:
    repeat()