彩色数字相机快速自动曝光方法  

Fast Automatic Exposure Approach for Color Digital Camera

作　　者：郭惠楠[1,2] 曹剑中[1] 周祚峰[1] 廖加文 刘庆[1] 

机构地区：[1]中国科学院西安光学精密机械研究所,陕西西安710119 [2]中国科学院大学,北京100049

出　　处：《光学学报》2013年第10期107-113,共7页Acta Optica Sinica

基　　金：国家自然科学基金(61201376);陕西省自然科学基金(2012JQ8003)

摘　　要：彩色数字相机的曝光准确度直接影响了图像的色彩表现及人眼视觉的感受效果。提出了一种基于人眼视觉感观特性的相机自动曝光方法。通过对图像清晰度、色彩饱和度以及亮度等因素的客观评价,建立了曝光估计函数。根据统计原理并结合经验公式,对曝光估计值与曝光步长增量之间的函数关系进行标定,确立了曝光增量函数。根据当前帧图像的不同亮度属性,结合曝光增量函数,实时计算下一帧所需要的理想曝光值。大量实验表明,该方法对于不同场景、不同光照条件下图像的曝光量都有良好的调节效果,稳健性较强并具有较高的调节效率。Exposure accuracy of color digital camera directly affects the performance of color image and the sensory effects of human visual. An automatic exposure method of digital camera based on the color perceiving properties of human visual system, is proposed. A novel kind of exposure estimation function is also established through objective evaluating the sharpness, color saturation and brightness of input images. According to the statistical theory and empirical formulas, the functional relationship between the exposure estimation values and exposure step increment is calibrated and the exposure increment function is established as well. For different brightness properties of current frame, using the exposure increment function, the ideal exposure value of next frame in real time is calculated. A large number of experimental results show that the proposed method for different scenes and different lighting conditions always has a good performance in adjusting exposure value of the captured image. Meanwhile, the algorithm has good robustness which can achieve adjustment for input frames in short time.

关 键 词：图像处理 光学工程 自动曝光 评价函数 亮度 数字相机 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]