基于亮度校正模型的多参量权衡与灰度权值算法研究

Research on Multi Parameters and Gray Weight Algorithm Based on The Brightness Correction Model

针对嵌入亮度校正模型的全彩LED显示屏低灰度均匀性差甚至会出现缺少灰度等级的问题,研究了校正算法实施过程中的多维参量,分析了红绿蓝三基色校正参量偏差和扫描图像数据偏差产生的原因及其对各灰度级亮度差值的影响。最后基于LED显示屏驱动控制系统提出参量的权衡公式,根据权衡公式选取各参量最优值,并针对图像数据的最小进位精度这一参量提出一种高精度灰度权值算法,不仅可提高显示屏各灰度下的均匀性指标,而且还可增加LED显示屏上的显示灰度等级。实测结果表明:当选取校正参量的校正精度为8 bit、图像数据的最小进位精度为0.5时,8扫显示屏不能达到均匀性指标的灰度级区间为[42,1];按照权衡公式选取校正参量的校正精度为10 bit、图像数据的最小进位精度为0.25时,均匀性不能达到指标的灰度级区间减小到[20,1],同时相比前者,LED显示屏的起辉级数减小,显示灰度等级增加两级。

Multi parameters are studied in full color LED dispaly panel,which is bothered by the uniformity of gray level while implementation of brightness correction algorithm. The main causes of deviation for brightness correction parameter and image data correction are analyzed,which have serious influence on brightness deviation of gray level. Moreover,a balance algorithm of parameters is proposed,based on which the optimal parameters are selected that can improve uniformity of all gray level and increase gray color. For practicing,accuracy value of the correction parameters is selected as 8 bits,and minimum gray level accuracy of the image data is 0. 5,then the interval of image data is [42,1],based on uniformity index of 97%. Similarly,accuracy value of the correction parameters is selected as 10 bits,and minimum gray level accuracy of the image data is 0. 25,then the interval of image data reduces to [20,1]. Obviously,two gray level of LED display panel is increased.