1. A method for adding transparency to an object based rasterized image composed of a plurality of objects including edge information, level information and transparency information, said method comprising the steps of: (a) receiving edge intersection data for each of the plurality of objects that intersect a current raster line of the image and determining which corresponding objects are active at a current pixel position; (b) determining a highest active opaque object level for all the currently active objects; (c) determining a highest active transparent object level for all the currently active objects; (d) outputting object level information corresponding to the highest active opaque object level; and (e) simultaneously outputting transparency information corresponding to the currently active object having a higher level of the highest active opaque object level and the highest active transparent object level.