Python Opencv VideoCapture::read returns None only in a virtual environment

edit savecancel

Btw, If ur pc is 64-bit, u don't need 0xff

cool, but not sure if this helps me...

Thank you for your suggestion. This did not fix my issue - Using Windows 10, Python 3.6.3 OpenCV3, and suggestions?

@MachineLearner. Sorry, I didn't see your comment. What's OpenCV version you have? I'm using OpenCV 3.3.1

Supra56, thank for replying - I have python 3.6.1 and opencv 3.3.1 loaded, windows 10. New to Python and OpenCV. I am having issues getting simple examples to work. I.e this thread for one example.

@MachineLearner. Can u post code?

@MachineLearner. Sorry for delay, because of halloween. Don't cv2.startWindowThread() Never put inside looping. cap.release() cv2.destroyAllWindows()

here is code:

import cv2
cap = cv2.VideoCapture(0)
while(1):
    _, frame = cap.read()
    cv2.imshow('frame',frame)        
    k = cv2.waitKey(1)
    if k == 27: break

cap.release()
cv2.destroyAllWindows()

For second code. The programming didn't added waikey(0) Here is code:

import cv2
import numpy as np

img_rgb = cv2.imread('opencv-template-matching-python-tutorial.jpg')
img_gray = cv2.cvtColor(img_rgb, cv2.COLOR_BGR2GRAY)

template = cv2.imread('opencv-template-for-matching.jpg',0)
w, h = template.shape[::-1]
res = cv2.matchTemplate(img_gray,template,cv2.TM_CCOEFF_NORMED)
threshold = 0.7 
loc = np.where( res >= threshold)
for pt in zip(*loc[::-1]):
    cv2.rectangle(img_rgb, pt, (pt[0] + w, pt[1] + h), (0,255,25), 2)

    cv2.imshow('Detected',img_rgb)
cv2.waitKey(0)