OpenCV_TypeError: 'NoneType'对象没有属性'__getitem__'

I was using OpenCV 2.4.6 and was running the following code successfully from OpenCV Python Tutorial-

我使用OpenCV 2.4.6，并成功地从OpenCV Python教程中运行以下代码。

    import numpy as np
import cv2
cap = cv2.VideoCapture('slow.flv')
ret,frame = cap.read()

r,h,c,w = 250,90,400,125  # simply hardcoded the values
track_window = (c,r,w,h)
roi = frame[r:r+h, c:c+w]
hsv_roi =  cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
mask = cv2.inRange(hsv_roi, np.array((0., 60.,32.)), np.array((180.,255.,255.)))

roi_hist = cv2.calcHist([hsv_roi],[0],mask,[180],[0,180])
cv2.normalize(roi_hist,roi_hist,0,255,cv2.NORM_MINMAX)

term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 )

while(1):
ret ,frame = cap.read()

if ret == True:
    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
    dst = cv2.calcBackProject([hsv],[0],roi_hist,[0,180],1)

    # apply meanshift to get the new location
    ret, track_window = cv2.meanShift(dst, track_window, term_crit)

    # Draw it on image
    x,y,w,h = track_window
    img2 = cv2.rectangle(frame, (x,y), (x+w,y+h), 255,2)
    cv2.imshow('img2',img2)

    k = cv2.waitKey(60) & 0xff
    if k == 27:
        break
    else:
        cv2.imwrite(chr(k)+".jpg",img2)

else:
    break

cv2.destroyAllWindows()
cap.release()

Later on I started to using OpenCV 3.0 and replace some Lib files in site packages directory and also replaced CV2.pyd file.Then when I tried to run the same code, i am getting the following error-

后来，我开始使用OpenCV 3.0，并在site packages目录中替换一些Lib文件，并替换了CV2。pyd文件。然后，当我尝试运行相同的代码时，我得到了以下错误。

Traceback (most recent call last): File "D:\Backup\OpenCV_Python_Prac_files\Prac5.1.1_ Video Analysis_MeanShift.py", line 14, in roi = frame[r:r+h, c:c+w] TypeError: 'NoneType' object has no attribute '_getitem_'

Traceback(最近的一个电话):File "D:\Backup\OpenCV_Python_Prac_files\Prac5.1.1_视频分析。在roi = frame[r:r+h, c:c+w]类型错误中:'NoneType'对象没有属性'_getitem_'。

Can anyone tell me what is the reason behind causing this problem? Thanks in Advance.

谁能告诉我造成这个问题的原因是什么?提前谢谢。

1 个解决方案

#1

The error says that your frame is None. Check the return value of the first call to cap.read

错误说明你的框架是空的。检查第一次调用cap.read的返回值。