超光滑表面瑕疵的光学显微成像和数字化评价系统

提出了利用一种特殊设计的LED多光束环状分布照明光源,与显微镜组成超光滑表面元件缺陷检测的光学显微散射成像系统,获取适合于数字图像二值化处理的暗背景上的亮瑕疵图像.利用X、Y,两方向的精密移导系统对表面实施子孔径图像的扫描.在原有的子孔径图像拼接边缘拓展法算法的基础上,提出一种基于特征分类的多层次图像拼接算法.该算法分为特征分类和多层次拼接两个部分:通过重叠区域内特征的提取和分类,将所有子孔径图像的重叠区域分为四类;然后针对这四类重叠区域的不同特点,有次序地进行图像拼接,最终得到全景图像.并应用二元光学制作了标准比对板,以获得瑕疵正确的数字化评价依据.实验结果证明:该系统和算法特别适合在被测表面范围较大、具有微米量级分辨率的瑕疵的数字化定量检测和评价.

Optical microscopic imaging and digitized evaluation system for super-smooth surface defects

An optical microscopic scattering imaging system was proposed in this paper.It was combined by ring distribution of multi-beam LED light source and a microscope system.An image ofbright defects in black background was obtained,which was suitable for binary-state processing of digital image.Full aperture measurement could be obtained by X,Y sub-aperture scanning system.A multi-cycle image mosaic algorithm based on both feature classification and the previousedge-expansion methodwas proposed,which would be divided into four typos for overlapping regions of the entire sub-aperture image.Then the multi-cycle mosaic was conducted according to different defect features distribution in the overlapped region.Therefore,A full aperture image could be obtained.A group of standard reticules were fabricated by binary optics.It could be used to calibrate the scale of the defects.Experimental results show that the system and the mosaic algorithm for images of defects are suitable for detection and evaluation of the large aperture fine surface.