points as noted the spatial key is a conventional technology for performing spatial indexing and search a spatial key covers a defined geographic area that may be larger than the visible area displayed by the map therefore the map image also preferably encodes a bounding box in an alternative embodiment a bounding area u2014 capable of accommodating more than two points u2014 is used web crawling search engine 102 records the spatial key and the bounding box of the map an initial query executed against the search engine index may extract urls from a range of spatial key values sub filtering may be performed to eliminate urls with bounding boxes that fall outside the area of interest of a query fig4 illustrates how bounding boxes 402 404 406 may be entirely within the area of interest 408 e g bounding box 404 entirely outside the area of interest e g bounding box 402 or bounding boxes may intersect the area of interest e g bounding box 406 we now provide an example of how to steganographically encode a 32 bit spatial key and a spatial bounding box in the red green and blue rgb values of a hypothetical bitmap image although we use a 32 bit.