Xu Jing, Tian Xiaolin, Meng Xin, Kong Yan, Gao Shumei, Cui Haoyang, Liu Fei, Xue Liang, Liu Cheng, Wang Shouyu
Jiangnan University, School of Science, Department of Optoelectronic Information Science and Enginee, China.
Shanghai University of Electric Power, College of Electronics and Information Engineering, Shanghai, China.
J Biomed Opt. 2017 Aug;22(8):1-7. doi: 10.1117/1.JBO.22.8.086012.
Massive image acquisition is required along the optical axis in the classical image-analysis-based autofocus method, which significantly decreases autofocus efficiency. A wavefront-sensing-based autofocus technique is proposed to increase the speed of autofocusing and obtain high localization accuracy. Intensities at different planes along the optical axis can be computed numerically after extracting the wavefront at defocus position with the help of the transport-of-intensity equation method. According to the focus criterion, the focal plane can then be determined, and after sample shifting to this plane, the in-focus image can be recorded. The proposed approach allows for fast, precise focus detection with fewer image acquisitions compared to classical image-analysis-based autofocus techniques, and it can be applied in commercial microscopes only with an extra illumination filter.
在基于经典图像分析的自动聚焦方法中，需要沿光轴进行大量图像采集，这显著降低了自动聚焦效率。为了提高自动聚焦速度并获得高定位精度，提出了一种基于波前传感的自动聚焦技术。借助强度传输方程方法在离焦位置提取波前之后，可以通过数值计算沿光轴不同平面处的强度。根据聚焦准则，随后可以确定焦平面，并且在将样品移动到该平面之后，可以记录清晰聚焦的图像。与基于经典图像分析的自动聚焦技术相比，所提出的方法能够以较少的图像采集实现快速且精确的焦点检测，并且仅需额外的照明滤光片即可应用于商用显微镜。
