import cv2
import numpy

cap = cv2.VideoCapture(2)

cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)

while True:
    _, frame = cap.read()
    grey = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    t1 = cv2.adaptiveThreshold(grey, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY_INV, 3, 7)
    t2 = cv2.adaptiveThreshold(grey, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY_INV, 13, 7)
    t3 = cv2.adaptiveThreshold(grey, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY_INV, 23, 7)

    threshed = numpy.concatenate((t1, t2, t3), axis=1)
    cv2.imshow('threshed', threshed)
    cv2.waitKey(1)