在数字共焦显微技术的图像反卷积复原中，三维点扩展函数(3D-PSF)空间大小的选取与图像复原效果有密切的关系。依据显微镜三维成像原理以及3D-PSF模型，分析了显微镜3D-PSF的能量分布和3D-PSF空间大小的关系，提出了一种通过复原效率与能量关系曲线拐点进行能量阈值确定，以实现3D-PSF空间大小选取的方法。模拟了生物光学显微镜3种不同数值孔径(放大倍数)物镜下图像的采集和3D-PSF的生成，获取不同能量大小3D-PSF对细胞三维仿真图像的反卷积复原结果。提出的方法为三维显微图像反卷积复原中3D-PSF的自动选取奠定了基础。

In the image deconvolution of digital confocal microscopy system, the selection of spatial size of three dimensional point spread function (3D-PSF) is closely related to the effect of image restoration. Based on the principle of three- dimensional microscopic imaging and 3D- PSF model, the relationship between the energy distribution and the size of 3D-PSF is analyzed, and a 3D-PSF size selection method is proposed and realized, which uses the restoration efficiency - energy curve inflection point for energy threshold determination. The acquisition of image and the generation of 3D-PSF of bio-optical microscope objective of three kinds of numerical aperture or magnification are simulated, and the deconvolution restoration results of three-dimensional simulated cell images by using the 3D-PSFs with different energy are obtained. The experimental results show the effectiveness and feasibility of the proposed method, and provide a basis for automatic selection of 3D-PSF for the three-dimensional microscopic image deconvolution.