1. python2.7 is installed on ubuntu2. apt-get install python-pip3.pip install numpy sklearn4.apt-get install libopencv-dev5.apt-get install libcv-dev6.apt-get install python-opencv7. test:     --->import cv2    --->img = cv2.imread("demo.jpg")
    --->cv2.imwrite("new-demo.jpg", img)    if you get new-demo.jpg it says python+opencv ok
8. pip install imutils9. test usb camera    camera = cv2.VideoCapture(0)    img = camera.read()
    cv2.imwrite("capture.jpg", img)