text: import cv2
  import matplotlib.pyplot as plt
  import numpy as np
  
  __author__ = 'Luqman'
  
  
  class PointValueScatter(object):
      red_values = None
      green_values = None
      blue_values = None
      gray_values = None
  
      def __init__(self):
          self.red_values = []
          self.green_values = []
          self.blue_values = []
          self.gray_values = []
  
      def fetch_point_value(self, image, x, y):
          gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
          self.red_values.append(image[y, x, 2])
          self.green_values.append(image[y, x, 1])
          self.blue_values.append(image[y, x, 0])
          self.gray_values.append(gray_image[y, x])
  
      def plot_histogram(self):
          plt.hist(self.gray_values, color='gray')
          plt.show()
  
          plt.hist(self.red_values, color='red')
          plt.hist(self.green_values, color='green')
          plt.hist(self.blue_values, color='blue')
          # plt.plot(self.gray_values)
          plt.show()
          pass
  