A data processing apparatus has a first compressor, a second compressor, a first output interface, and a second output interface. The first compressor generates first compressed display data by performing compression upon display data of a first partial region of a frame according to a first compression order. The second compressor generates second compressed display data by performing compression upon display data of a second partial region of the frame according to a second compression order. There is a boundary between the first partial region and the second partial region. In a horizontal direction, the first compression order on one side of the first boundary is opposite to the second compression order on another side of the first boundary. The first and second output interfaces output the first and second compressed display data via a first display port and a second display port of a display interface, respectively.