The NCSA Imagemap Format

  Keyword  URL          Coordinates

  rect       your_url_here  x,y x,y     

  circle     your_url_here  x,y x,y

  oval       your_url her   x,y, x,y

  poly       your_url_here  x,y … x,y

  point      your_url_here  x,y

Rectangles are specified by their left, top, right and bottom coordinates.

Circles are specified by their center point, and an edge point.

Ovals are specified by their left, top, right and bottom coordinates.

Polygons are specified by a list of vertices.

Points are specified by their center point.