import cv2
import numpy as np
def nothing(x):
    print(x)
img=np.zeros((300,512,3), np.uint8)
cv2.namedWindow("image")  #use to create a window with a name
cv2.createTrackbar("B", "image", 0,255,nothing)
cv2.createTrackbar("G", "image", 0,255,nothing)
cv2.createTrackbar("R", "image", 0,255,nothing)
#switch="0: OFF\n 1: ON"
cv2.createTrackbar("0: OFF\n 1: ON", "image", 0,1,nothing)
while(1):
    cv2.imshow("image", img)
    k=cv2.waitKey(1) & 0xFF
    if k==27:
        break
    b=cv2.getTrackbarPos("B", "image")
    g = cv2.getTrackbarPos("G", "image")
    r = cv2.getTrackbarPos("R", "image")
    s = cv2.getTrackbarPos("0: OFF\n 1: ON", "image")
    if s==0:
        img[:]=0
    else:
        img[:]=[b,g,r]

    #img[:]=[b,g,r]
cv2.destroyAllWindows()