大尺寸薄壳物体表面的三维光学自动检测

报道一种大型薄壳物体的智能光学三维测量以及自动在线检测方法,利用三节点光学测量传感器网络实现了大型薄壳物体内外表面数据的三维重建、特征尺寸获取及计算机辅助设计(CAD)模型的比对.提出一种有效的三维多节点传感器测量网络的系统标定方法,可同时完成整体测量系统在大尺度测量空间的现场标定以及各个三维节点测量传感器的标定.提出...     

借助标志点的深度数据全局匹配方法

深度数据匹配是三维光学测量系统的关键问题,借助标志点匹配方法具有廉价、方便、快速等优点,但当前该方法对多视场数据匹配的误差积累问题没有解决.阐述一种借助非编码标志点进行深度数据匹配的方法,利用图像处理及模式识别技术提取标志点,并由光学测量系统标定信息获得标志点三维局部坐标,利用欧式空间距离的刚体不变性,完成两个视场深度数据的精确匹配.并提出一种全局迭代优化算法完成对多个视场深度数据的全局精确匹配,避免了误差积累,最大匹配误差从0.123 mm降到0.076 mm.实验证实了方法的有效性,不仅可以自动、快速完成两个视场深度数据的精确匹配,而且解决了对多个视场深度数据匹配的误差积累问题.     

基于相位辅助的三维数字成像与测量

综述了基于相位辅助的三维数字成像与测量的核心技术.以相机模型为基础,建立了三维数字成像系统模型和三维测量网模型,并介绍了相关的标定技术.在主动立体视觉的理论框架下,综述了相位提取、相位展开、对应点搜索等单视点深度像重建的关键技术.介绍了深度数据后处理技术,其中包括多视点深度像的匹配、融合和简化的代表性算法.同时,对系统...     

Multiple-image encryption by two-step phase-shifting interferometry and spatial multiplexing of smooth compressed signal

A multiple-image encryption method based on two-step phase-shifting interferometry(PSI) and spatial multiplexing of a smooth compressed signal is proposed. In the encoding and encryption process, with the help of four index matrices to store original pixel positions, all the pixels of four secret images are firstly reordered in an ascending order; then, the four reordered images are transformed by five-order Haar wavelet transform and performed sparseness operation. After Arnold transform and pixels sampling operation, one combined image can be grouped with the aid of compressive sensing(CS)and spatial multiplexing techniques. Finally, putting the combined image at the input plane of the PSI encryption scheme,only two interferograms ciphertexts can be obtained. During the decoding and decryption, utilizing all the secret key groups and index matrices keys, all the original secret images can be successfully decrypted by a wave-front retrieval algorithm of two-step PSI, spatial de-multiplexing, inverse Arnold transform, inverse discrete wavelet transform, and pixels reordering operation.