A method, medium, and system compressing and/or reconstructing image data. The data compression method includes compressing current data according to a plurality of modes for compressing current data, determining whether the current data compressed according to the plurality of modes can be represented by a fixed length of bits, selecting a mode from among modes in which the compressed current data can be represented by the fixed length of bits, and outputting the compressed current data according to the selected mode. Accordingly, it is possible to significantly lower the complexity of an image encoder/decoder system, and exactly meet a picture-based Control Bit Rate (CBR) suitable for a Liquid Crystal Display Dynamic Capacitance Compensation (LCD DCC) device/system.