Patent ID: 6940518

Claim:
A method for interactively viewing and editing a digital image on a computer system comprising the steps of: storing an archival digital image in the computer system; maintaining in the computer system a state list, characterizing a sequence of image-editing operations to be applied to the archival digital image in order to generate a current edited rendition of the digital image; maintaining in the computer system a set of viewing data, chracterizing the resolution, offset and extent at which to view the current edited rendition of the archival digital image; maintaining in the computer system a cache of image tiles comprising portions of views of edited renditions of the archival digital image, wherein each image tile is associated with a state in the list; and thereafter updating, in response to image-viewing and image-editing instructions, the viewing data and the state list accordingly, and assembling in the image tile cache in response to image-viewing and image-editing instructions, a set of image tiles sufficient to generate the current view of the current edited rendition of the archival digital image, wherein assembling comprises using the stare list to compute a current tile based on an image tile associated with a previous state.