colour_maker_using_trackbar[bgr values].py

import cv2
import numpy as np

def current(x):
    print(x)



img=np.zeros((512,512,3),np.uint8)

cv2.namedWindow('image')

cv2.createTrackbar('B','image',0,255,current)
cv2.createTrackbar('G','image',0,255,current)
cv2.createTrackbar('R','image',0,255,current)

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')

    img[:] = [b,g,r]

cv2.destroyAllWindows()