随着光学信息处理技术的发展,图像边缘检测技术在光学高对比度成像、自动驾驶、人脸识别、天文观测等领域得到了广泛的应用。光学边缘检测主要是借助4-f空间滤波成像系统,通过在傅里叶平面上加载滤波器来修改图像的频谱信息,进而实现物体边缘轮廓的提取。介绍了几种不同光学图像边缘检测方式,进行了简要的理论分析,并总结了国内外的相关研究进展。

The application of dark-field (DF) technique with adaptive optics for retinal imaging in vivo is presented to improve retinal imaging contrast. The influence on the imaging contrast introduced by dynamic ocular aberrations should be considered. The qualitative analysis of the influence is discussed. Detail simulation and quantitative analysis are presented. According to our simulation results, when residual aberrations are reduced to less than 5%, it has a little impact on the contrast of DF imaging; while, on increasing the aberrations up to 10%, the contrast of the DF imaging falls off sharply.

The Ronchi grating is applied to measure the large-aperture aspheric surfaces in a quantitative way on the basis of self-made software which includes Ronchi null grating design, collection of Ronchi graph, and data processing. The measured concave parabolic mirror has a diameter of 630 mm and an F number of 1.34. The measurement result is approximately the same as that of the ZYGO interferometer. This analysis software and test method establish a good foundation for the quantitative measurement of the big error about the large-aperture aspheric surfaces of the next generation telescope.

Varietal purity is the most important quality parameter of maize seeds, which has direct and prominent influence on the output and quality of maize. For the first time, to our knowledge, we present a new kind of terahertz (THz) scanning imaging technology for identification of maize seeds. Terahertz images of DNA samples are obtained by point-by-point scanning imaging technology. Inspection and identification of specific kinds of seeds are realized successfully by using the method of component pattern analysis. In this method, what we need are only data of image and absorption spectral information of samples; no specific features of samples are required. This technology provides a new approach for the detection and identification in biology and it can also be extended to poison inspection.