A method for data compression provides for an improved digital facsimile document transmission system. The mixed mode method provides that symbols can be located both individually and as a part of a line of symbols in order to provide for efficient operation for both the symbol and graphic portions...http://www.google.com.au/patents/US5847841?utm_source=gb-gplus-sharePatent US5847841 - Mixed-mode symbol removal for facsimile data compression
