An efficient content adaptive backlight control algorithm for local dimming liquid crystal displays

In this paper, a novel high-performance low-complexity content adaptive backlight control (CABC) algorithm is proposed for local dimming in liquid crystal displays (LCDs). There are two kinds of dimming algorithms, changing transmittance to affect backlight power and enhancing the gray level of the displaying images, to control the driving current of the backlight LED array. In order to improve the performance of the proposed backlight control algorithm, the proposed algorithm combined both ideas of increasing the transmittance and improving gray level of the displaying images. To increase the flexibility for the users, the proposed algorithm consists of a low-power and high-quality modes for different situations. Moreover, in order to reduce the complexity of the proposed algorithm, a look-up-table technique was used to replace high-complexity equations, such as root operation, with a fixed table. Compared with previous CABC algorithms, the proposed algorithm reduced the average power reduction rate at least by 7.2% and improved the average PSNR value by over 6.75 dB.