gistfile1.py

import cv2
import numpy as numpy
import sys
h = 512
w = 512

def nothing(x):
	pass

cv2.namedWindow('lena')
cv2.namedWindow('result')
img = cv2.imread('lena.png')
dst = numpy.zeros((w,h,3),numpy.uint8)

# create trackbars for color change
cv2.createTrackbar('R','result',0,255,nothing)
cv2.createTrackbar('G','result',0,255,nothing)
cv2.createTrackbar('B','result',0,255,nothing)

while(1):
	for i in range(0,w):
		for j in range(0,h):
			dst[i,j,0] = img[i,j,0]/255.0*cv2.getTrackbarPos('B','result')
			dst[i,j,1] = img[i,j,1]/255.0*cv2.getTrackbarPos('G','result')
			dst[i,j,2] = img[i,j,2]/255.0*cv2.getTrackbarPos('R','result')
	cv2.imshow('result',dst)
	cv2.imshow('lena',img)
	k = cv2.waitKey(0) & 0xFF
	if k == 27: #esc
		break

cv2.destroyAllWindows()