Fractal Image Coding for Thumbnail Based Image Access

A variant of block-oriented fractal coding termed thumb fractal is introduced that essentially is the Jacquin-Barnsley block-oriented fractal code for the (signed) difference image between the target image and the image thumbnail exploded to fullsize. Thumb fractal code involves fewer block parameters than other fractal coding, as data from the image thumbnail is utilised in image generation. Using domain block to range block size ratio of 4 for thumb fractal code yields a super-fast converging codec, with initial image the exploded thumb. This codec is especially suitable for thumbnail-based image access, where image retrieval is preceded by thumbnail access and diaply.