一种新的能量谱熵图像聚焦评价函数

New Kind of Energy Spectrum Entropy Image Focusing Evaluation Function

针对计算机视觉中图像聚焦评价函数的选择与设计问题，首先对图像聚焦评价函数的基本概念和特征进行了讨论，然后对目前几种主要的图像聚焦评价函数（ 灰度变化函数、梯度函数、图像灰度熵函数、频域类函数） 进行了分析．在此基础之上提出了一种新的能量谱熵函数评价方法，并且给出了相应的计算公式．该函数的理论依据较之目前常用的评价函数更为充分，最后给出了与其它几种主要评价函数的实验对比结果，证明了能量谱熵函数比其它评价函数在评价图像聚焦质量方面更为准确、稳定和可靠．

To counter the selection and design of image focusing evaluation functions in the field of computer vision, the fundamental concept and characteristics of image focusing evaluation functions are introduced firstly. Then some kinds of current main image focusing evaluation functions (such as gray scale variation function, gradient function, image gray scale entropy function, frequency domain function) are analyzed. On the base of above discussion, a new kind of energy spectrum entropy image focusing evaluation function is presented, and the corresponding mathematical formulae are also given. The theoretical foundation of this function is more sufficient than current other ordinary functions. Finally, the experimental results of energy spectrum entropy function are compared with other functions, the result indicates that the energy spectrum entropy function is more accurate, stable and reliable in the evaluation of the quantity of image focusing.