python opencv調色板

# -*- coding: utf-8 -*-

import numpy as np
import cv2

def nothing(x):
	pass
	
def palette():
	img=np.zeros((300,1378,3),np.uint8)
	cv2.namedWindow('image')
	cv2.createTrackbar('R','image',0,255,nothing)
	cv2.createTrackbar('G','image',0,255,nothing)
	cv2.createTrackbar('B','image',0,255,nothing)
	
	switch='0:OFF\n1:ON'
	cv2.createTrackbar(switch,'image',0,1,nothing)
	
	#print(img)
	
	while True:
		cv2.imshow('image',img)
		k=cv2.waitKey(1)&0xFF
		if k == 27:
			break
		
		r=cv2.getTrackbarPos('R','image')
		g=cv2.getTrackbarPos('G','image')
		b=cv2.getTrackbarPos('B','image')
		s=cv2.getTrackbarPos(switch,'image')
		
		if(s == 0):
			img[:] = 0
		else:
			img[:]=[b,g,r]
	
	cv2.destroyAllWindows()

def main():
	palette()

if __name__ == '__main__':
	main()