侧入式发光二极管背光区域调光算法

A Local Dimming Algorithm for Edge-lit Lighting Emitting Diode Backlight

为解决液晶显示存在能效和对比度不高问题,本文结合主流背光结构和区域调光技术优势,提出了一种侧入式LED背光区域调光算法,包括背光调光、亮度分配和像素补偿三个部分。调光算法将输入图像进行分区,计算每个分区的图像亮度;亮度分配算法引入资源分配和运输模型建立图像分区亮度到LED灯串亮度的映射关系。像素补偿算法使用低通滤波器模拟得到LED发出的光经导光板、扩散膜后的扩散效果,据此调整液晶像素亮度。并对该算法进行了大量的仿真实验,开发了原理性样机。对30幅典型图像实际测试表明,平均节能率为20.57%,平均结构相似性性能参数为0.985。本文提出的侧入式区域调光算法既能保持背光结构轻薄,同时具有较好的节能和显示效果。

To solve the shortcomings of low energy efficiency and contrast of traditional LCDs, and considering the advantages of mainstream backlight construct and local dimming technology, a local dimming algorithm for edge-lit LED backlight is proposed. The method consists of three parts： backlight level dimming, LED allocation and pixel compensation algorithm. In backlight level dimming algorithm, the input image is divided into several blocks and each block image luminance is calculated. Then a resource allocation and transport model is introduced to establish the mapping relationship between block luminance and LED strings in allocation algorithm. In pixel compensation, first, the backlight diffusion effect of the light guide plate（LGP） and diffusion film is acquired from simulated with low-pass filters. Then, the LC pixel is compensated based on original image pixel and backlight effect. The algorithm is simulated, and a TV prototype is developed to test actual display effect. The actual test results show that the average power reduction reaches 20.57% and the Structural Similarity（SSIM） of original and dimmed image is 0.985. The proposed algorithm presents a good power saving and display effect as well as light and thin backlight structure.