基于一体化摄像机的清晰度评价函数研究

清晰度评价函数的选择是一体化摄像机实现对焦,以获取高质量图像很重要的依据。针对一体化摄像机的实时性和简易行,对几种常用的清晰度评价函数算法分别从高效性、无偏性、单峰性和灵敏度等进行了较全面的性能比较。分析结果表明:Laplace函数和Brenner函数的峰顶宽度相对较窄,灵敏度高,因此适合于小范围精确调焦。Tenengrad函数、Robert函数和平方梯度的峰顶相对较宽,在焦点附近具有比较高的灵敏度,同时也有一定的调焦范围,适于中等范围的自动调焦,这对于一体化摄像机所需要的自动调焦控制具有指导意义。

The research of focusing evaluation function based on the room camera

Focusing evaluation function is important as to the room camera to achieve the focus of image and get high-quality image.We have a comprehensive performance comparison of several commonly used focusing evaluation functions, quantitative analysis of the efficiency of different algorithms including no bias, single peak and sensitivity according to the simplicity and real-time.The results showed that： Brenner functions and Laplace function is suitable for small-scale precision focusing for its relatively narrow peak width, high sensitivity.Tenengrad function, Robert function and squared gradient function is suitable for mid-range auto-focus, because they have relatively high sensitivity, and also they have a certain focus range.It＇s instructive to the room camera to achieve automatic focusing.