The initialization module for the cgImageGroup object creates a specific
  instance of the object.
 

Params

---

    image: in, required, type=varies
      A 2D or true-color image variable to display and interact with. Optionally,
      this variable may also be the name of an image file that IDL can open with
      READ_IMAGE.
 

Keywords

---

    filename: in, optional, type=string
        The name of an IDL image file that IDL can read with READ_IMAGE.
    reverse: in, optional, type=boolean, default=0
        Set this keyword to reverse the image in the Y direction before display.