A method and device for data compression are presented, in which a data processor may receive a packet of image data which includes four groups of N bits, where N is an integer greater than 2. The data processor may compress the received packet of data, such that a total number of bits for the converted packet is less than four times N. The data processor may compress the received packet of image data by reducing the resolution of three of the values while maintaining the resolution of the fourth value. To reduce the resolution of the three values, the data processor may apply a dithering formula to the values. The data processor may then send the converted packet via an interface.