code: import numpy as np
  
  # prewitt x and y filters
  PREWITTX = np.array([[-1, 0, 1], [-1, 0, 1], [-1, 0, 1]], np.float32)
  PREWITTY = np.array([[-1, -1, -1], [0, 0, 0], [1, 1, 1]], np.float32)
  
  # Sobel x and y filters
  SOBELX = np.array([[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]], np.float32)
  SOBELY = np.array([[-1, -2, -1], [0, 0, 0], [1, 2, 1]], np.float32)
  
  
apis: numpy.array