A design of a cost-effective look-up table for RGB-to-RGBW conversion

Abstract

RGBW domain is widely used to improve the brightness of display panels without their increasing power consumption. RGBW display systems use a look-up table (LUT) for fast RGB-to-RGBW conversion. However, the LUT is implemented by a large size memory and thereby incurring high hardware cost. To reduce the size of the LUT, data mapping in the LUT are sub-sampled, which results in large errors in data conversion. Based on the piecewise-linear characteristic in color change, the sub-sampled data are linearly interpolated. In addition, the interpolation performance is improved by utilizing distribution patterns of color components. Experimental results show that the average of the mean square errors by the proposed method is 21.72 when the size of the LUT decreases to 1/215 of the original LUT size.