中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共6条，第1-6条

帮助

条数/页：排序方式：
	A line mapping based automatic registration algorithm of infrared and visible images 会议论文 OAI收割 5th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Infrared Imaging and Applications, Beijing, June 25-27, 2013 作者: Ai R(艾锐); Shi ZL(史泽林); Xu DJ(徐德江); Zhang CS(张程硕) 收藏 \| 浏览/下载：63/0 \| 提交时间：2013/12/26 There exist complex gray mapping relationships among infrared and visible images because of the different imaging mechanisms. The difficulty of infrared and visible image registration is to find a reasonable similarity definition. In this paper, we develop a novel image similarity called implicit linesegment similarity(ILS) and a registration algorithm of infrared and visible images based on ILS. Essentially, the algorithm achieves image registration by aligning the corresponding line segment features in two images. First, we extract line segment features and record their coordinate positions in one of the images, and map these line segments into the second image based on the geometric transformation model. Then we iteratively maximize the degree of similarity between the line segment features and correspondence regions in the second image to obtain the model parameters. The advantage of doing this is no need directly measuring the gray similarity between the two images. We adopt a multi-resolution analysis method to calculate the model parameters from coarse to fine on Gaussian scale space. The geometric transformation parameters are finally obtained by the improved Powell algorithm. Comparative experiments demonstrate that the proposed algorithm can effectively achieve the automatic registration for infrared and visible images, and under considerable accuracy it makes a more significant improvement on computational efficiency and anti-noise ability than previously proposed algorithms.
	Rigorous vector analysis of diffractive microlens by using of finitedifference time-domain method (EI CONFERENCE) 会议论文 OAI收割 2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China 作者: Liu Y.; Liu H.; Liu H.; Liu H.; Liu Y. 收藏 \| 浏览/下载：57/0 \| 提交时间：2013/03/25 We use finite difference time domain (FDFD) method as rigorous vector analysis model to simulate the focusing process of diffractive microlens (DML). Differing with most analysis model which the near field distributions are calculated by FDTD and then far field are obtained by using of propagation method we obtain the fields in whole computational space by using of FDTD only. The advantages are that all the results are vector based and the computational time is saved greatly. In this paper we present two methods to obtain wave amplitude one is comparison method and the other is integral method. Depending on wave amplitude in the whole computational space one can conveniently obtain distributions of electric field intensity and calculate the time-average Poynting vector. We also present the formulation for calculating diffractive efficiency of DML based on time-average Poynting vector which denotes energy flow. As demonstration a DML is analyzed by using of these algorithms. The time depended graphic results of FDTD show the process of wave propagation. The distribution of electric field intensity illustrates the focusing of the normal incident light. The focus pattern in the focal plane is also show. The diffractive efficiency of the DML is calculated by using of the energy flow method in this paper. The results show the high accuracy and efficiency of the model. 2009 SPIE.
	Modeling of satellite borne TDI CCD pitching imaging image motion velocity vector (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Automation and Logistics, ICAL 2009, August 5, 2009 - August 7, 2009, Shenyang, China 作者: Zhang L.; Li S.; Zhang L. 收藏 \| 浏览/下载：36/0 \| 提交时间：2013/03/25 In order to obtain three-dimensional observation effect with single satellite borne time delay and integrate charge coupled device (TDI-CCD) pitching imaging is required. More accurate real-time image motion velocity vector computational model of space camera is also necessary to make the imaging perfect. Imaging motion velocity vector computation model must be set up on image plane at pitching imaging. According to the geometric relationship between the pitching imaging space camera and the Earth's rotation motion satellite borne TDI CCD pitching imaging motion velocity vector model is derived by mapping the ground speed to the image plane and using coordinate transformation method. The numerical simulation results show that the image velocity model can reduce deviation angle error about 33' and about 30% image motion speed error compared to traditional ground velocity model. 2009 IEEE.
	Real time tracking by LOPF algorithm with mixture model (EI CONFERENCE) 会议论文 OAI收割 MIPPR 2007: Automatic Target Recognition and Image Analysis; and Multispectral Image Acquisition, November 15, 2007 - November 17, 2007, Wuhan, China Meng B.; Zhu M.; Han G.; Wu Z. 收藏 \| 浏览/下载：49/0 \| 提交时间：2013/03/25 A new particle filter-the Local Optimum Particle Filter (LOPF) algorithm is presented for tracking object accurately and steadily in visual sequences in real time which is a challenge task in computer vision field. In order to using the particles efficiently we first use Sobel algorithm to extract the profile of the object. Then we employ a new Local Optimum algorithm to auto-initialize some certain number of particles from these edge points as centre of the particles. The main advantage we do this in stead of selecting particles randomly in conventional particle filter is that we can pay more attentions on these more important optimum candidates and reduce the unnecessary calculation on those negligible ones in addition we can overcome the conventional degeneracy phenomenon in a way and decrease the computational costs. Otherwise the threshold is a key factor that affecting the results very much. So here we adapt an adaptive threshold choosing method to get the optimal Sobel result. The dissimilarities between the target model and the target candidates are expressed by a metric derived from the Bhattacharyya coefficient. Here we use both the counter cue to select the particles and the color cur to describe the targets as the mixture target model. The effectiveness of our scheme is demonstrated by real visual tracking experiments. Results from simulations and experiments with real video data show the improved performance of the proposed algorithm when compared with that of the standard particle filter. The superior performance is evident when the target encountering the occlusion in real video where the standard particle filter usually fails.
	A Computational Model for Two-stage 4K-Pulse Tube Cooler: Part I.Theoretical Model and Numerical Method 期刊论文 OAI收割 JOURNAL OF THERMAL SCIENCE, 2001, 卷号: 10, 期号: 4, 页码: 342347 Y.L. Jul; A.T.A.M. de Waele2 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/12 4K-pulse tube cooler two-stage computational model.
	A Computational Model for Two-stage 4K-Pulse Tube Cooler: Part I.Theoretical Model and Numerical Method 期刊论文 OAI收割 JOURNAL OF THERMAL SCIENCE, 2001, 卷号: 10, 期号: 4, 页码: 342347 作者: Y.L. Jul; A.T.A.M. de Waele2 \| 收藏 \| 浏览/下载：35/0 \| 提交时间：2013/03/12 4k-pulse Tube Cooler Two-stage Computational Model.