SYSTEM FOR MANAGING TILED IMAGES USING MULTIPLE RESOLUTIONS

An image memory management system for tiled images. The system defines an address space for a virtual memory that includes an image data cache and a disk. An image stack for each source image is stored as a full resolution image and a set of lower-resolution subimages. Each tile of an image may exist in one or more of five different states as follows: uncompressed and resident in the image data cache, compressed and resident in the image data cache, uncompressed and resident on disk, compressed and resident on disk and not loaded but re-creatable using data from higher-resolution image tiles.