Image Processing
OpenCV is a library of programming functions mainly aimed at real-time computer vision. Let’s create a window which will contain RGB color palette with track bars. By moving the trackbars the value of RGB Colors will change b/w 0 to 255. So using the same, we can find the color with its RGB values.
Create a black window with three color channels with resolution 512 x 512. Then create three ‘B’ ‘G’ ‘R’ trackbars using predefined functions of OpenCV library. Set the values of channels from 0 to 255. Merging the black window with these color trackbars.
openCV and numpy
# Python program to create RGB color palette with trackbars importing libraries
import cv2
import numpy as np
# empty function called when any trackbar moves
def emptyFunction():
pass
def main():
# blackwindow having 3 color chanels
image = np.zeros((512, 512, 3), np.uint8)
windowName ="Open CV Color Palette"
# window name
cv2.namedWindow(windowName)
# there trackbars which have the name
# of trackbars min and max value
cv2.createTrackbar('Blue', windowName, 0, 255, emptyFunction)
cv2.createTrackbar('Green', windowName, 0, 255, emptyFunction)
cv2.createTrackbar('Red', windowName, 0, 255, emptyFunction)
# Used to open the window
# till press the ESC key
while(True):
cv2.imshow(windowName, image)
if cv2.waitKey(1) == 27:
break
# values of blue, green, red
blue = cv2.getTrackbarPos('Blue', windowName)
green = cv2.getTrackbarPos('Green', windowName)
red = cv2.getTrackbarPos('Red', windowName)
# merge all three color chanels and
# make the image composites image from rgb
image[:] = [blue, green, red]
print(blue, green, red)
cv2.destroyAllWindows()
# Calling main()
if __name__=="__main__":
main()
