def kml_png(mapping):
    """
    Create text for a png file overlay
    """

    kml_text = """
<GroundOverlay>
<name>{name:s}</name>
<visibility>1</visibility>
<gx:altitudeMode> clampToSeaFloor </gx:altitudeMode>
<Icon>
  <href>{png_file:s}</href>
</Icon>
<LatLonBox>
  <north>{y2:.9f}</north>
  <south>{y1:.9f}</south>
  <east>{x2:.9f}</east>
  <west>{x1:.9f}</west>
</LatLonBox>
</GroundOverlay>
""".format(**mapping)

    return kml_text