Reduction of quantization errors caused by dynamic LCD backlight scaling

Abstract

Dynamic backlight scaling (DBS), a technique for LCD power reduction, often deteriorates image quality because of a flicker (unintended temporal variation of the luminance) generated in the frame at which the backlight level changes. This paper proposes a novel DBS algorithm to reduce the flicker by decreasing the quantization errors (QEs) that are created in the multiplication of the input gray level and the DBS scaling ratio as well as in the mapping of the multiplication result to an integer gray level. The proposed DBS algorithm reduces the QE down to 28.8% when compared with the conventional DBS algorithm.

Image-classification-based global dimming algorithm for LED backlights in LCDs

“…Lai and Tsai [16] calculated the global dimming level by the grayscale that consists of 75% all pixels. The global dimming level in [17] is decided by pixel clipping rate. In [18], the clipping rate is determined by the characteristic features of the image.…”