1. A pixel processing apparatus, comprising: a frame storage unit in which input pixel data is stored in frame/field units; a line storage unit in which the input pixel data, which is stored in the frame storage unit in frame/field units, is stored in line units per vertically-divided segment; a processor that pre-processes or post-processes the input pixel data stored in the line storage unit; and a controller that divides the input pixel data within a frame, which is stored in the frame storage unit, into a plurality of segments in a vertical direction, and sequentially stores the input pixel data in the line storage unit in a sequence of segments in line units.