Subdivides an image into tiles and computes the corresponding sectors. The width and height of the returned tiles can
be specified but default to 1024. If the base image width or height is not evenly divisible by the corresponding
desired tile dimension, tiles along the right and bottom of the base image may contain pixels that do not correspond
to pixels in the image. These pixels will have an alpha component of 0 and the corresponding tile will have an alpha
channel. Otherwise tiles will not have an alpha channel. If the input image is already the desired subimage size, it
is returned without being copied.
Performs a subdivision according to the current parameters and assuming that the image corresponds with a Sector rather than a quadrilateral or other shape. Conveys each tile created to the caller via a listener
baseImage - the image to tile.
baseSector - the sector defining the geographic extent of the base image.
listener - the listener to invoke when each new tile is created.