METHOD OF PREPARING BIT MAP

摘要

A method of preparing a second bit map, improved in first−direction resolution, from a first bit map having a plurality of image−forming pixels arranged two−dimensionally, the method comprising the first detection step of detecting first and second edges appearing in a second direction orthogonal to a first direction from a first bit map, and the first addition step of adding an edge extending in the first direction, when a portion between the first and second edges permits interpolation, to between third and fourth edges on the second bit map respectively corresponding to the first and second edges so as to effect interpolation between the third and fourth edges. Since the first and second edges, if detected, permit smoothing, a look−up table is not needed, and even a long−cycle unevenness can be smoothed without a smoothing range being limited to a predetermined region.