Perceived Distortion-Based Progressive LCD Backlight Dimming Method

This paper presents a backlight dimming algorithm based on the distortion corresponding to the viewing distance. Unlike the existing methods, the proposed method determines the clipping point depending on the perceived distortion which the viewer recognizes depending on the viewing distance. The proposed method consists of the following three steps. In the first step, for clipping point selection, the proposed method eliminates the imperceptible details which the viewers cannot recognize easily. In the second step, the proposed method finds the critical block which is most likely to cause the clipping artifacts. Then, the proposed method selects a clipping point which maintains the perceived distortion of the critical block below the viewer's threshold. In the final step, the output backlight luminance and pixel data are determined using the selected clipping point. The experimental results showed that the performance of the proposed method was similar to those of benchmark methods at a short viewing distance. On the other hand, the proposed method significantly reduced the power consumption at a long viewing distance, while properly preserving the image quality, compared to the benchmark methods. Specifically, the proposed method decreased the power consumption by more than 30% at the 4 m distance, compared to the benchmark methods, while preserving the perceived image quality beyond 97.4%.