中国科学院机构知识库网格系统: 检索

Scene- and pixel-level analysis of Landsat cloud coverage and image acquisition probability in South and Southeast Asia 期刊论文 OAI收割
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION, 2023, 卷号: 123, 页码: 13
作者: Yang, Yin; Li, Peng

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收藏 | 浏览/下载：20/0 | 提交时间：2024/03/25

Landsat Cloud coverage Image acquisition probability Coarse -and -fine thresholding Scene and pixel -level South and Southeast Asia

A sub-pixel extraction method for the center of the circular structure from spot array calibration target (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者: Liu Y.; Zhang T.; Yang H.; Gao X.; Liu Y.

收藏 | 浏览/下载：83/0 | 提交时间：2013/03/25

The imaging measurement system must be calibrated before application. In calibration procedure sub-pixel center extraction is the crucial step for the final accuracy. In this paper a new sub-pixel extraction method is proposed. Edge detection at pixel level is obtained using LOG operator then sub-pixel edge detection is realized using the Facet model. Finally the least squares ellipse fitting is operated on the sub-pixel edge to determine the sub-pixel center. Experiment on a series of simulated images indicates that this algorithm is able to realize the center location accuracy of 0.01-0.02 pixel and meets the requirement of sub-pixel level. (2012) Trans Tech Publications Switzerland.

Study on sub-pixel techniques for accurate image measurement of displacement (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Advanced Measurement and Test, AMT 2011, June 24, 2011 - June 26, 2011, Nanchang, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

The high resolving power camera was often used to improve the precision of measuring system although its price is high because the accuracy of image measure was limited by the pixel resolving ability of camera. A method of one dimension gray level quadrature sub-pixel to detect edge was presented. This method was applied to measure the displacement of measuring head on 3-coordinate measuring machine. The data of test was shown that this system can distinguish displacement 0.001mm. it is higher accuracy than pixel level. So this method is convenient and fast fit to track and measure the moving object. It is obvious that this method can save the cost of hardware.

A new research of sub-pixel level accuracy of TDICCD remote sensing image registration (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: He B.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

In the field of remote sensing imaging TDICCD remote sensing images have a lot of their own characteristics such as high-resolution large amount of information less overlapping parts of pixels additional image blurring etc. Therefore there exist many difficulties especially in terms of high-accuracy registration of pairs of images. For that this paper presents two new pixel interpolation method for sub-pixel level registering images that allows for scaling translation and rotation. The proposed technique which is based on the maximization of the correlation coefficient function combines an efficient pixel-moving interpolation scheme with surface fitting which greatly reduces the overall computational cost. The accuracy of the algorithm is evaluated by calculating correlation coefficient of couples of points belonging to images transformed with preset factors and also comparing it to other sorts of methods. The experiment results show that the accuracy of registration reaches 0.01 pixels. 2010 IEEE.

The registration of aerial infrared and visible images (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Educational and Information Technology, ICEIT 2010, September 17, 2010 - September 19, 2010, Chongqing, China
作者: Liu J.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

In order to solve the registration problem of different source image existed on aerial image fusion algorithms based on Particle Swarm Optimization (PSO) are applied as search strategy in this paper and Alignment Metric (AM) is used as judgment. This study has realized the different source image registration of infrared and visible light with high speed high accuracy and high reliability. Basically with little restriction of gray level properties a new alignment measure is applied which can efficiently measure the image registration extent and tolerate noise well. Even more the intelligent optimization algorithm - Particle Swarm Optimization (PSO) is combined to improve the registration precision and rate of infrared and visible light. Experimental results indicate that the study attains the registration accuracy of pixel level and every registration time is cut down over 40 percent compared to traditional method. The match algorithm based on AM solves the registration problem that greater differences between different source images are existed on gray and characteristic. At the same time the adoption of combining the intelligent optimization algorithms significantly improves the searching efficiency and convergence speed of the algorithms and the registration result has higher accuracy and stability which builds up solid foundation for different source image fusion. The method in this paper has a magnificent effect and is easy for application and very suitable for engineering use. 2010 IEEE.

Study on dynamic imaging on TDI CCD optical remote sensor of push-broom technology (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者: Liu L.; Ren J.-Y.; Liu L.; Gao M.-H.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

A set special detecting system is proposed based on TDICCD push-broom technology applying in dynamic imaging detecting experiment of space optics remote sensor. In the system In the course of detecting push-broom movement of the satellite is simulated through using double supporting U structure precision rotary platform with remote sensor by angular speed 0.555/s regard Nyquist frequency target as detecting aim within the range of 5 and control precision on steady speed achieves 0.3% in order to solve matching uncertainty between the CCD pixel and the vertical target strip image when the remote sensor does push-broom make matching simplify enhance the measurement result the accuracy. So the tolerance a/n arithmetic progression gap target strip is joined in each group of rectangular vertical group target strip. The remote sensor obtains in vertical the level and 45 the direction 0 fields of view 0.86 the field of view Nyquist frequency target strip image after detected a group target strip which can precision matching to TDICCD pixel at least can be obtained through analysis and dealing with 0.86 field of view's target strip image. The experiment not only verifies the detecting system's feasibility but simultaneously verifies whether to have the high quality dynamic imaging quality when TDICCD push-broom technology is adopted on the remote sensor developed. 2010 Copyright SPIE - The International Society for Optical Engineering.

Level 0 and level 1 data processing for a type of hyper-spectral imager (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 21, 2009, Shanghai, China
Li X.; Yan C.

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Hyper-spectral imaging (HSI) is a kind of optical remote sensor that can simultaneously obtain spatial and spectral information of ground targets. We are now designing a data processing system for a type of space-borne push-broom HSI then it performs radiometric and spectral calibration based on the ground calibration results and onboard calibration collection. The detailed algorithms for bad pixel replacement which has 128 spectral channels covering the spectral range from 400nm to 2500nm. With its large amount of spectral channels radiometric and spectral calibration were presented. After processing the HSI collects large volume of spectral imaging data need to be efficiently and accurately processed and calibrated. In this paper the digital numbers downlinked from the spacecraft can be converted into at-sensor absolute spectral radiance of ground targets the detailed Level 0 and Level 1 data processing steps for the HSI were presented. The Level 0 processing refers to a set of tasks performed on the data downlinked from the spacecraft thus providing accurate quantified spectral imaging data for various applications. 2009 SPIE. including decoding to extract science data separating the science data into files corresponding to different tasks (e.g. ground imaging dark imaging and onboard calibration) checking data integrity and instrument settings data format conversion and Level 0 files creation. The Level 1 processing performs several steps on Level 0 data. Firstly it corrects the image artifacts (mostly the SWIR smear effect) subtracts the dark background and performs the bad pixel replacement according to the prelaunch measurement

A MLP-PNN neural network for CCD image super-resolution in wavelet packet domain (EI CONFERENCE) 会议论文 OAI收割
2008 International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2008, October 12, 2008 - October 14, 2008, Dalian, China
Zhao X.; Fu D.; Zhai L.

收藏 | 浏览/下载：79/0 | 提交时间：2013/03/25

Image super-resolution methods process an input image sequence of a scene to obtain a still image with increased resolution. Classical approaches to this problem involve complex iterative minimization procedures typically with high computational costs. In this paper is proposed a novel algorithm for super-resolution that enables a substantial decrease in computer load. First decompose and reconstruct the image by wavelet packet. Before constructing the image use neural network in place of other rebuilding method to reconstruct the coefficients in the wavelet packet domain. Second probabilistic neural network architecture is used to perform a scattered-point interpolation of the image sequence data in the wavelet packet domain. The network kernel function is optimally determined for this problem by a MLP-PNN (Multi Layer Perceptron - Probabilistic Neural Network) trained on synthetic data. Network parameters dependent on the sequence noise level. This super-sampled image is spatially Altered to correct finite pixel size effects to yield the final high-resolution estimate. This method can decrease the calculation cost and get perfect PSNR. Results are presented showing the quality of the proposed method. 2008 IEEE.

Design of dual-FOV refractive/diffractive LWIR optical system (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
作者: Wang L.-J.; Zhang J.-P.

收藏 | 浏览/下载：46/0 | 提交时间：2013/03/25

An infrared-optical zoom system using binary element is proposed in this paper. The two main advantages of the zoom system introducing here are: bigger F-number and lower cost. The primary optical properties are: F/#=1 Second Others zoom ratio =1:4 binary element is used to correct the chromatical aberration by taking the advantage of negative dispersion characteristics and the cost of the system is lower than that of conventional ones with Zinc Selenide (Znse) material at the same level. In the binary element is rotational symmetric with one step which is easy to fabricate in order to balance 5th spherical aberration and dual field are 26.6 and 5.6respectively. Wider field of view is used for search and the smaller one is used for imaging details. This system uses un-cooled infrared detector with 320240 pixels and 45m pixel size. The F-number matches the sensitivity range of the detector array. Three aspects are considered during design process to make the system more satisfactory and more achievable. First 5th coma aberration and 5th astigmatic aberration the manner of zoom is accomplished by exchanging tow lenses into the smaller field of view system layout. The lens exchange manner faces the requirement of simple system structure and good image quality in both focal points. It can also make the system more feasible in the alignment process than mechanical-zooming manner and optical-zooming manner high-order asphere surfaces with 2th order to 10 th order are also hired in the system. Asphere surface is useful in compressing the system and improving optical system transmittance. This kind asphere surface is on industrial level featuring low cost and easy to fabricate. It is shown that good image quality can achieved by implementing five Germanium lenses and the transmittance of system is 72%. All aberrations are diffraction-limited both spherical aberration and astigmatic aberration are corrected. When the field of view(FOV) is 26.6 and the focal length is 152mm MTF at Nyquist frequency(11lp/mm) is great than 0.7. The spherical aberration is -0.0073. The coma aberration is 0.0978 and the astigmatic aberration is -0.013. When the field of view(FOV) is 5.6 and the focal length is 38mm MTF at Nyquist frequency is great than 0.8 with spherical aberration -0.0046 the coma aberration 0.055 and astigmatic aberration 0.034.

Multiwavelet based multispectral image fusion for corona detection (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者: Wang X.; Yang H.-J.; Sui Y.-X.; Yan F.; Yan F.

收藏 | 浏览/下载：48/0 | 提交时间：2013/03/25

Image fusion refers to the integration of complementary information provided by various sensors such that the new images are more useful for human or machine perception. Multiwavelet transform has simultaneous orthogonality symmetry compact support and vanishing moment which are not possible with scalar wavelet transform. Multiwavelet analysis can offer more precise image analysis than wavelet multiresolution analysis. In this paper a new image fusion algorithm based on discrete multiwavelet transform (DMWT) to fuse the dual-spectral images generated from the corona detection system is presented. The dual-spectrum detection system is used to detect the corona and indicate its exact location. The system combines a solar-blind UV ICCD with a visible camera where the UV image is useful for detecting UV emission from corona and the visible image shows the position of the corona. The developed fusion algorithm is proposed considering the feature of the UV and visible images adequately. The source images are performed at the pixel level. First a decomposition step is taken with the DMWT. After the decomposition step a pyramid for each source image in each level can be obtained. Then an optimized coefficient fusion rule consisting of activity level measurement coefficient combining and consistency verification is used to acquire the fused coefficients. This process reduces the impulse noise of UV image. Finally a new fused image is obtained by reconstructing the fused coefficients using inverse DMWT. This image fusion algorithm has been applied to process the multispectral UV/visible images. Experimental results show that the proposed method outperforms the discrete wavelet transform based approach.