Research on the technology of femtosecond laser micromachining based on image edge tracing

Aiming at fabrication of complex microstructures and micro-patterns, a kind of femtosecond laser micromachining technology based on the BMP image edge tracing was proposed. We introduced the general principle of this technology and discussed the implementation of the machining paths extraction, optimization, tracing and the feedback of the machining procession in detail. On the basis of this technology, control software for femtosecond laser micromachining was developed. Furthermore, we have accomplished the fabrication of complicated two-dimensional (2D) micro-patterns on a copper thin film. The results indicate that this technology can be used for digital control micromachining of complex patterns or microstructures at micron and submicron scales by femtosecond laser.     

基于子模式纹理分析的鲁棒人脸识别研究

面部识别(FR)系统可以自动识别或校验从数码相机或图像生成设备中获得的人脸图像,要从所获图像中提取面部特征,并与人脸数据库中的数据进行比对。目前,几乎所有的FR都面临与面部视角相关的障碍,包括光照不足和低分辨率,这些问题使其识别率大为降低。为了解决这个问题,提出了一种基于光照变化的人脸识别框架,该框架利用离散余弦变换的图像全变差最小化(DTV)及伽柏过滤器;并融合子模式分析(SMP)及区分性累计特征变换(DAFT),有效地解决了光照条件变化大的人脸识别问题。在AR及YaleB人脸数据库上的实验表明,与其它最先进的方法相比较,在处理光照条件变化很大的人脸识别问题时明显优于其它方法。