Procedure ImageGrayout(image)
  Protected w, h, x, y, r, g, b, gray, color

  w = ImageWidth(image)
  h = ImageHeight(image)
  StartDrawing(ImageOutput(image))
  For x = 0 To w - 1
    For y = 0 To h - 1
      color = Point(x, y)
      r    = Red(color)
      g    = Green(color)
      b    = Blue(color)
      gray = 0.2126*r + 0.7152*g + 0.0722*b
      Plot(x, y, RGB(gray, gray, gray)
    Next
  Next
  StopDrawing()
EndProcedure

Procedure ImageToColor(image)
  Protected w, h, x, y, v, gray

  w = ImageWidth(image)
  h = ImageHeight(image)
  StartDrawing(ImageOutput(image))
  For x = 0 To w - 1
    For y = 0 To h - 1
      gray = Point(x, y)
      v    = Red(gray) ;for gray, each of the color's components is the same
      ;color = RGB(0.2126*v, 0.7152*v, 0.0722*v)
      Plot(x, y, RGB(v, v, v))
    Next
  Next
  StopDrawing()
EndProcedure