GENERIC PRE-PROCESSING OF MIXED RASTER CONTENT PLANES

A mixed raster content system and method improves the performance of the compression process by reducing the amount of data. The system and method uses a selector plane as a reference to aid in reducing the amount of data necessary to encode each of associated planes. A smoothing technique is used to pre-process the associated planes using the information contained in the selector plane, thereby reducing the amount of data that will be subjected to further processing. The system and method determines the useless data, smooths the boundary of the useless data, and replaces the useless data by values that improve compression.