中国科学院机构知识库网格系统: 检索

基于神经辐射场的室内三维重建方法研究 学位论文 OAI收割
2024
作者: 刘湘龙

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收藏 | 浏览/下载：20/0 | 提交时间：2024/05/28

Neural implicit representation Indoor reconstruction Geometric priors Multi-resolution voxel grid Pose optimization

Deep Bayesian local crystallography 期刊论文 OAI收割
NPJ COMPUTATIONAL MATERIALS, 2021, 卷号: 7, 期号: 1
作者: Kalinin, Sergei, V; Oxley, Mark P.; Valleti, Mani; Zhang, Junjie; Hermann, Raphael P.

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收藏 | 浏览/下载：21/0 | 提交时间：2021/12/01

ELECTRON-MICROSCOPY IMAGES GEOMETRIC PHASE-ANALYSIS CHEMICAL-IDENTIFICATION MACROSCOPIC SYMMETRY MAGNETIC-PROPERTIES UNIT-CELL RESOLUTION CRYSTALS GLASSES PHYSICS

A shrunken edge algorithm for contact detection between convex polyhedral blocks 期刊论文 OAI收割
COMPUTERS AND GEOTECHNICS, 2015, 卷号: 63, 页码: 315-330
作者: Wang J(王杰); Li SH(李世海); Feng C(冯春)

收藏 | 浏览/下载：43/0 | 提交时间：2015/03/17

Contact detection Polyhedral block Geometric resolution Contact type Shrunken edge Approaching face

Advanced astigmatism-corrected tandem Wadsworth mounting for small-scale spectral broadband imaging spectrometer (EI CONFERENCE) 会议论文 OAI收割
作者: Lin G.-Y.

收藏 | 浏览/下载：38/0 | 提交时间：2013/03/25

Tandem gratings of double-dispersion mount make it possible to design an imaging spectrometer for the weak light observation with high spatial resolution high spectral resolution and high optical transmission efficiency. The traditional tandem Wadsworth mounting is originally designed to match the coaxial telescope and large-scale imaging spectrometer. When it is used to connect the off-axis telescope such as off-axis parabolic mirror it presents lower imaging quality than to connect the coaxial telescope. It may also introduce interference among the detector and the optical elements as it is applied to the short focal length and small-scale spectrometer in a close volume by satellite. An advanced tandem Wadsworth mounting has been investigated to deal with the situation. The Wadsworth astigmatism-corrected mounting condition for which is expressed as the distance between the second concave grating and the imaging plane is calculated. Then the optimum arrangement for the first plane grating and the second concave grating which make the anterior Wadsworth condition fulfilling each wavelength is analyzed by the geometric and first order differential calculation. These two arrangements comprise the advanced Wadsworth mounting condition. The spectral resolution has also been calculated by these conditions. An example designed by the optimum theory proves that the advanced tandem Wadsworth mounting performs excellently in spectral broadband. 2012 Optical Society of America.

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：36/0 | 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.

Effect of the sampling design of ground control points on the geometric correction of remotely sensed imagery SCI/SSCI论文 OAI收割
2012
作者: Ge Y.

收藏 | 浏览/下载：23/0 | 提交时间：2014/12/24

Geometric correction Spatial coverage sampling Universal kriging Variogram Model-based sampling resolution satellite imagery accuracy registration algorithm model

EXTRACTION OF OBJECT FEATURES FROM HIGH RESOLUTION SAR IMAGES BASED ON SURF FEATURES 会议论文 OAI收割
2011 Ieee International Geoscience and Remote Sensing Symposium, New York
Tian, Xiaonjuan; Wang, Chao; Zhang, Hong

收藏 | 浏览/下载：22/0 | 提交时间：2014/12/07

Feature Extraction high resolution SAR SURF description geometric features

Image compression based on contourlet and no lists SPIHT (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: Zhang S.

收藏 | 浏览/下载：46/0 | 提交时间：2013/03/25

The volume of raw image data captured by the high resolution camera is extremely huge. Thus the efficient image compression method should be used to decrease the bit rate. The image compression method based on wavelet is used more widely nowadays. However two dimensional wavelet is only the tensor product of the one dimensional wavelet whose support region of basis function is extended from interval to square. Contourlet is an image multiscale geometric analysis tool which could represent image sparsely and has strong capability of nonlinear approximation. The basis function of contourlet is multidirectional and anisotropic. Nevertheless contourlet is redundant. So the non-redundant Wavelet Based Contourlet Transform (WBCT) is used in this paper. The SPIHT algorithm is very efficient way to coding the significant coefficients. And the improved no lists SPIHT is more easy to implemented by hardware. Image compression method based on the combination of both wavelet based contourlet transform and no lists SPIHT coding is proposed in the paper. Experiment shows that compared to wavelet based scheme the contourlet scheme can reserve the texture of the image. For barbara test image when coding at low bit rate the PSNR can improve about 0.2dB. 2010 IEEE.

Design of aspherical surfaces for panoramic imagers using multipopulations genetic algorithm (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Jin C.-S.; Wang L.-P.; Liang Z.-Z.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

A design method of aspherical surface for panoramic imaging system with two mirrors using multi-populations genetic algorithms is proposed. Astigmatism induced by mirrors may significantly compromise image resolution. To solve this problem we induced algebraic expression of astigmatism in panoramic imager based on generalized Coddington equation and theory of geometric optics. Then we propose an optimization process for mirror profile design to eliminate astigmatism and provide purposely-designed projection formula with aid of MPGA. A series of polynomial expressions of aspherical surfaces are obtained and procedures of the design are presented. In order to facilitate ray tracing and aberration calculation even asphere surface model is obtained by using of hybrid schemes combining MPGA and damped least squares. Finally a prototype of the catadioptric panoramic imager has been developed and panoramic ring image is obtained. 2009 SPIE.

Contrast research on interpolation and subpixel imaging in CCD geometric superresolution reconstruction (EI CONFERENCE) 会议论文 OAI收割
1st Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics, PrimeAsia 2009, November 19, 2009 - November 21, 2009, Shanghai, China
作者: Xu Y.-S.; Yang S.-W.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

In order to enhance the resolution of Charge Coupled Device (CCD) pixel with the pixel dimension and focal length of optical system unchanged the problem of CCD geometric superresolution is educed. The problem is discussed in terms of software and hardware. In software the bicubic interpolation is introduced while in hardware the subpixel imaging method is utilized. The subpixel imaging method integrates two uniform linear CCDs staggered by half dimension of pixel in one device. In operation the line frequency is doubled. At last the collected data is interweaved to synthesize a high resolution image. The two methods bicubic interpolation and subpixel imaging are simulated with Matlab7.0.1. The qualitative and quantitative analyses are given. The simulated results of lanczos and cubic spline interpolation methods are given simultaneously to show the performance of interpolation. The simulation result shows that the result images quality becomes better in both methods but compared with bicubic interpolation method the synthesized image PSNR gained from sub-pixel imaging is averagely enhanced by 2.1682dB while the elapsed time is reduced to be about one forth. The subpixel imaging method could significantly mitigate the image blur introduced by undersample. 2009 IEEE.