code: def main(argv):
      fn = "defaultimage.jpg"
      if len(argv) > 1:
          fn = argv[1]
  
      loadImage(fn)  # Loading the image
  
      initGL()
      initData(fn)
      print(
          """
      Q: Exit
      I: display image
      T: display Sobel edge detection (computed with tex)
      S: display Sobel edge detection (computed with tex+shared memory)
      D: display Sobel edge detection (computed with tex+shared memory+fixed block size)
      Use the '-' and '=' keys to change the brightness.
  
      TESTED WITH IMAGE SIZE OF 512x512... just like the original demo.
      Other image sizes may not work
      """
      )
      glutDisplayFunc(display)
      glutKeyboardFunc(keyboard)
      glutReshapeFunc(reshape)
      glutIdleFunc(idle)
      glutMainLoop()
  
imports: from OpenGL.GL import *
  from OpenGL.GLUT import *
  from OpenGL.GLU import *
  from OpenGL.GL.ARB.vertex_buffer_object import *
  import numpy, Image
  import sys, time, os
  import pycuda.driver
  import pycuda.gl
  import pycuda
  from pycuda.compiler import SourceModule
label_desc: Use image node_id 11 for calling a global function with example usage: main(argv) without return types