NEW METHODS FOR IMAGE TWO-TONE REPRESENTATION AND FOR GRAPH DATA COMPRESSION

摘要

A new method using a difference operator before taking the dither pattern processing is presented to improve the traditional two-tone representation of a multi-gray level picture.The net like points are reduced,this will be helpful in further compression process.A way using a difference comparison to improve the DTED method suggested by T.H.Morrin is also given in this paper,our method is proved theoretically and in experiment to be better than the original DTED method.For graph data compression a new run length method using variable length of counter is suggested to improve an ordinary one.The compression ratio has increased.A new vector method is also used for graph data compression,we pay a special attention to X-cross points to reduce the terminals.This new method is easier to realized.