我正在使用OpenCV和CentOS，我正在使用Python测试OpenCV模块，我的相机是IPEVO P2V，代码：
import numpy as np
import cv2
a = 0
for i in range(-2000, 2000):
t = cv2.VideoCapture(i)
ret, t1 = t.read()
if(ret==True):
a = i
break
print(a)
cap = cv2.VideoCapture(a)
count = 1
while (True):
# Capture frame-by-frame
ret, frame = cap.read()
# Our operations on the frame come here
# Display the resulting frame
cv2.imshow('frame', frame)
if cv2.waitKey(1) & 0xFF == ord('c'):
file = "/home/cro/test%d.png" % (count)
cv2.imwrite(file,frame)
count = count + 1
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
但出现错误：
OpenCV Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /home/cro/opencv-3.0.0/modules/highgui/src/window.cpp, line 271
Traceback (most recent call last):
File "camera_test.py", line 21, in <module>
cv2.imshow('frame', frame)
cv2.error: /home/cro/opencv-3.0.0/modules/highgui/src/window.cpp:271: error: (-215) size.width>0 && size.height>0 in function imshow
我检查了操作系统是否使用lsusb.py在/ usr / bin下找到了相机：
[cro@centos7-home ~]$ lsusb.py
usb1 1d6b:0002 09 2.00 480MBit/s 0mA 1IFs (Linux 3.10.0-327.36.3.el7.x86_64 xhci-hcd xHCI Host Controller 0000:00:14.0) hub
usb2 1d6b:0003 09 3.00 5000MBit/s 0mA 1IFs (Linux 3.10.0-327.36.3.el7.x86_64 xhci-hcd xHCI Host Controller 0000:00:14.0) hub
usb3 1d6b:0002 09 2.00 480MBit/s 0mA 1IFs (ehci_hcd 0000:00:1a.0) hub
3-1 8087:0024 09 2.00 480MBit/s 0mA 1IFs (Intel Corp. Integrated Rate Matching Hub) hub
3-1.1 1778:0204 ef 2.00 480MBit/s 300mA 3IFs (IPEVO corp IPEVO Point 2 View)
3-1.2 7392:7811 00 2.00 480MBit/s 500mA 1IFs (Realtek 802.11n WLAN Adapter 00e04c000001)
usb4 1d6b:0002 09 2.00 480MBit/s 0mA 1IFs (ehci_hcd 0000:00:1d.0) hub
4-1 8087:0024 09 2.00 480MBit/s 0mA 1IFs (Intel Corp. Integrated Rate Matching Hub) hub
4-1.4 0b05:17dc e0 2.10 12MBit/s 500mA 2IFs (Realtek Bluetooth Radio 00e04c000001)
似乎是OpenCV的问题，我该如何获得框架？