text: # USAGE
  # python drawing.py
  
  # Import the necessary packages
  import numpy as np
  import cv2
  
  # Initialize our canvas as a 300x300 with 3 channels,
  # Red, Green, and Blue, with a black background
  canvas = np.zeros((300, 300, 3), dtype = "uint8")
  
  # Draw a green line from the top-left corner of our canvas
  # to the bottom-right
  green = (0, 255, 0)
  cv2.line(canvas, (0, 0), (300, 300), green)
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Now, draw a 3 pixel thick red line from the top-right
  # corner to the bottom-left
  red = (0, 0, 255)
  cv2.line(canvas, (300, 0), (0, 300), red, 3)
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Draw a green 50x50 pixel square, starting at 10x10 and
  # ending at 60x60
  cv2.rectangle(canvas, (10, 10), (60, 60), green)
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Draw another rectangle, this time we'll make it red and
  # 5 pixels thick
  cv2.rectangle(canvas, (50, 200), (200, 225), red, 5)
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Let's draw one last rectangle: blue and filled in
  blue = (255, 0, 0)
  cv2.rectangle(canvas, (200, 50), (225, 125), blue, -1)
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Reset our canvas and draw a white circle at the center
  # of the canvas with increasing radii - from 25 pixels to
  # 150 pixels
  canvas = np.zeros((300, 300, 3), dtype = "uint8")
  (centerX, centerY) = (canvas.shape[1] // 2, canvas.shape[0] // 2)
  white = (255, 255, 255)
  
  for r in range(0, 175, 25):
  	cv2.circle(canvas, (centerX, centerY), r, white)
  
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)
  
  # Let's go crazy and draw 25 random circles
  for i in range(0, 25):
  	# randomly generate a radius size between 5 and 200,
  	# generate a random color, and then pick a random
  	# point on our canvas where the circle will be drawn
  	radius = np.random.randint(5, high = 200)
  	color = np.random.randint(0, high = 256, size = (3,)).tolist()
  	pt = np.random.randint(0, high = 300, size = (2,))
  
  	# draw our random circle
  	cv2.circle(canvas, tuple(pt), radius, color, -1)
  
  # Show our masterpiece
  cv2.imshow("Canvas", canvas)
  cv2.waitKey(0)