Compression of bi-level images with explicit representation of ink clusters

Abstract

A system and method facilitating compression of bi-level images with explicit representation of ink clusters is provided. The present invention includes a cluster shape estimator that analyzes connected component information, extracts clusters and stores the cluster in a global dictionary, a page dictionary or a store of unclustered shapes. A bitmap estimation from clusters component determines dictionary positions for clusters stored in the global dictionary which are then encoded. A cluster position estimator determines page positions of clusters of the global dictionary and/or the page dictionary that are then encoded. Further, the global dictionary, the page dictionary and the store of unclustered shapes are also encoded.

1 . A bi-level decoding system, comprising:
 a first decoder that decodes at least part of a bit stream, the first decoder decoding page positions;   a second decoder that decodes at least part of the bit stream, the second decoder decoding dictionary positions;   a third decoder that decodes at least part of the bit stream, the third decoder decoding a global dictionary of shapes and a page dictionary of shapes;   a fourth decoder that decodes at least part of the bit stream, the fourth decoder decoding a store of unclustered shapes;   a cluster generator that generates clusters based, at least in part, upon the page positions, dictionary positions and at least one of the global dictionary and page dictionary; and, a combiner that provides a bi-level output based, at least in part, upon the generated clusters and the store of unclustered shapes.   
     
     
         2 . The bi-level decoding system of  claim 1 , the first decoder employing, at least in part, upon bit-plane decoding. 
     
     
         3 . The bi-level decoding system of  claim 1 , the second decoder employing, at least in part, upon LZX decoding. 
     
     
         4 . The bi-level decoding system of  claim 1 , the third decoder employing, at least in part, upon lossless bi-level decoding. 
     
     
         5 . The bi-level decoding system of  claim 1 , the fourth decoder employing, at least in part, upon a lossless bi-level decoding. 
     
     
         6 . A method for bi-level decoding, comprising:
 decoding a page position;   decoding a dictionary position;   decoding a global dictionary; and,   generating a cluster based, at least in part, upon the page position, the dictionary position and the global dictionary to provide a bi-level output.   
     
     
         7 . The method of  claim 6 , further comprising at least one of the following acts:
 decoding a page dictionary;   decoding an unclustered shape;   combining the cluster and the unclustered shape to provide the bi-level output.   
     
     
         8 . (canceled) 
     
     
         9 . A computer readable medium storing computer executable components of a system for bi-level decoding, comprising:
 a first decoder that decodes at least part of a bit stream, the first decoder decoding page positions;   a second decoder that decodes at least part of the bit stream, the second decoder decoding dictionary positions;   a third decoder that decodes at least part of the bit stream, the third decoder decoding a global dictionary of shapes and a page dictionary of shapes;   a fourth decoder that decodes at least part of the bit stream, the fourth decoder decoding a store of unclustered shapes;   a cluster generator that generates clusters based, at least in part, upon the page positions, dictionary positions and at least one of the global dictionary and page dictionary; and,   a combiner that provides a bi-level output based, at least in part, upon the generated clusters and the store of unclustered shapes.   
     
     
         10 . (canceled)