离焦模糊图像清晰度评价函数的研究

Study on Clarity-evaluation-function of Out-of-focus Blurred Image

离焦模糊图像清晰度评价函数是采用数字图像处理技术实现显微镜自动调焦的一个关键 ,也是图像恢复中评价图像质量的一个重要判据。本文首次提出了用图像灰度梯度向量模方和、Roberts梯度和与拉普拉斯 (8邻域微分 )算子和作为由于离焦产生的模糊图像的评价函数。文中分别建立了上述几种评价函数的数学模型 ,给出了实验结果和分析。与以往的图像灰度熵和图像灰度方差评价函数相比 ,本文给出的评价函数无偏性好、单峰性强 。

The clarity- evaluation- function of out- of- focus blurred image is a key factor for auto- focusing of mi- croscope by using digital image processing,and it is also an important evaluation of the restoration quality of de- focused image.This paper firstly proposed some clarity- evaluation- functions of out- of- focus blurred image,they are the sum of square of gray- level gradient vector module,the sum of Roberts- gradients,and the sum of L apla- cian operator.The mathematical models are established individually,and the experimental results and analysis are also given.The clarity- evaluation- function of out- of- focus blurred image given here have the characteristics of non- deflection,unimodal,and high sensitivity.