Opencv：用Python导入highgui

Question

下面是一些代码：

import cv

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

def repeat():
  global capture #declare as globals since we are assigning to them now
  global camera_index
  frame = cv.QueryFrame(capture)
  cv.ShowImage("w1", frame)
  c = highgui.cvWaitKey(10)
  if(c=="n"): #in "n" key is pressed while the popup window is in focus
    camera_index += 1 #try the next camera index
    capture = cv.CaptureFromCAM(camera_index)
    if not capture: #if the next camera index didn't work, reset to 0.
        camera_index = 0
        capture = cv.CaptureFromCAM(camera_index)

while True:
    repeat()

出现了一个错误信息（Traceback），意思是最近的一次调用出错了： 文件 "pycam.py"，第21行，在 repeat() 这个函数里 文件 "pycam.py"，第12行，在 repeat 函数里 c = highgui.cvWaitKey(10) 这里出错了 NameError: global name 'highgui' is not defined 这个错误的意思是说，'highgui' 这个名字没有被定义，也就是说程序找不到这个东西。 最后，摄像头已经被清理了。

Answer 1

这意味着 highgui 这个东西不存在。你可以试着这样导入： from opencv import *。

如果这样还不行，建议你检查一下你的 opencv 安装情况。

Answer 2

新API有很多变化。下面的代码可以正常工作：

import cv

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

def repeat():
  global capture #declare as globals since we are assigning to them now
  global camera_index
  frame = cv.QueryFrame(capture)
  cv.ShowImage("w1", frame)
  c = cv.WaitKey(10)
  if(c=="n"): #in "n" key is pressed while the popup window is in focus
    camera_index += 1 #try the next camera index
    capture = cv.CaptureFromCAM(camera_index)
    if not capture: #if the next camera index didn't work, reset to 0.
        camera_index = 0
        capture = cv.CaptureFromCAM(camera_index)

while True:
    repeat()

这个语法更简单、更清晰了！