中国科学院机构知识库网格系统: 检索

Chinese Web users' daily image needs and seeking behavior in a Q&A community 期刊论文 OAI收割
chinese journal of library and information science, 2015, 卷号: 8, 期号: 1, 页码: 1-20
作者: HUANG Kun; NIU Xi; WANG Shanshan; WANG Kaifei

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Image needs Image seeking Baidu Zhidao Q&A communities Image users

Study on spectrograph for ionosphere: A broadband imaging instrument prototype for far-ultraviolet (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
作者: Wang S.-R.; Lin G.-Y.; Yu L.

收藏 | 浏览/下载：39/0 | 提交时间：2013/03/25

Current research on space-based exploration for the ionosphere needs more advanced technologies. Because the spectral signals in the ionosphere distributing basically in the far-ultraviolet waveband are very weak. Usual spectrometer structures and detectors such as CCD can't receive enough information. Based on this principle of atmospheric sounding the imaging spectrometer prototype for ionosphere detection application was designed to solve the problem. This prototype consists of the telescope and the imaging spectrometer. The simple structure and small number of mirrors can help higher transmission efficiency be achieved and weak signals detection be implemented. The telescope is an off-axis parabolic mirror and the spectrometer is a modified Czerny-Turner spectral imaging system. Modified Czerny-Turner spectrometer contains a spherical mirror a fixed plane grating and a toroidal mirror. By adjusting the incident angle to the collimating mirror and using toroidal mirror coma and astigmatism were corrected well. We also optimize distances between the grating to the focusing mirror and the focusing mirror to the image plane to improve disadvantages of traditional Czerny-Turner structure. Designed results demonstrate that aberrations are substantially corrected and high image quality can be obtained in broad waveband. The photon counting Wedge-Strip-Anode detector with micro-channel planes as the receiving plane is accepted for the instrument prototype. The other photon counting 2-D detector responding well for weak light such as Cross-Delay line detector and MAMA detector can also be used for detection. The calibration and performances testing system is made of a vacuum system a deuterium lamp a monochrometer and the instrument prototype. Results obtained from the experiment show that the spectral resolution is 2.4 nm and the spatial resolution is 80 m. The other calibration experiments are running. The technology of the spectrometer prototype is important for the research and applications of ionosphere remote sensing. 2011 SPIE.

A new method of target recognition based on rough set and support vector machine (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Image Analysis and Signal Processing, IASP'2010, April 12, 2010 - April 14, 2010, Xiamen, China
作者: He X.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

Automatic target recognition (ATR) is an important task in image application. This paper concentrates on two key subroutines of ATR system: Pre-treatment and design of classifier. In the pre-treatment subroutine a new method based on Rough Set (RS) is proposed to partition the original sample set into some subsets and calculate their class membership so that some samples can be chosen by class membership to be trained. After pre-treatment an iterative algorithm based on Rough Set and Support Vector Machines (IRSSVM) is introduced to design a classifier for recognizing two types of targets. The experiment results show that IRSSVM needs less training time and the classifier is simpler and has more generalization and higher recognition rate. 2010 IEEE.

Design and implementation of a high speed CMOS imaging system (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
作者: He X.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

In order to meet the needs of measurement of highspeed target the timing sequence of LUPA300 an array CMOS image sensor of CYPRESS is analyzed. The driving timing and control software is designed for the array CMOS sensor. High speed CMOS imaging system whose hardware platform is FPGA is emphasized. Real-time non-uniformity correction for CMOS sensor is implemented in the output stage. The experimental result shows that the system could control the CMOS sensor flexibly. The image is clear and stable. The maximum resolution of the image is 640H480V pixels and the system can operate up to 250 frames per second in full resolution. 2010 IEEE.

Fast color-transfer-based image fusion method for merging infrared and visible images (EI CONFERENCE) 会议论文 OAI收割
Multisensor, Multisource Information Fusion: Architectures, Algorithms, and Applications 2010, April 7, 2010 - April 8, 2010, Orlando, FL, United states
作者: Xu S.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

We present a computationally efficient color image fusion algorithm for merging infrared and visible images. At the core of the proposed method is the color transfer technique based on the linear YCBCR space. The method directly uses the grayscale fused image and the difference signals of the input images to construct the source YCBCR components then uses the statistical color transfer technique to form a color fused image that takes the target image's color characteristics. Two different strategies which respectively employ the pixel averaging fusion scheme and the multiresolution fusion scheme as the grayscale image fusion solution are proposed to fulfill different user needs. The simple strategy using the pixel averaging fusion scheme answers to a need of easy implementation and speed of use. And the complex strategy using the multiresolution fusion scheme answers to the high quality need of the fused products. In addition we also describe some useful theories about color-transfer-based image fusion. Experimental results show that the proposed color image fusion algorithm can effectively produce a natural appearing "daytime-like" color fused image and even using the pixel averaging fusion scheme to implement the grayscale fusion can also provide a pleasing result. 2010 Copyright SPIE - The International Society for Optical Engineering.

Optical design of reflecting telescope with large field (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Gong D.; Tian T.-Y.; Wang H.; Wang H.; Wang H.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

Reflecting telescopes have been widely used for many outstanding advantages. But the field of a common reflecting system is too small to meet the needs nowadays. When a correcting lens is inserted at the rear of R-C system the off-axis image quality is significantly improved. After optimizing with CODE V optical design software a new design scheme of reflecting telescope with large field of view is achieved. 2009 SPIE.

Self-adaptive threshold canny operator in color image edge detection (EI CONFERENCE) 会议论文 OAI收割
2009 2nd International Congress on Image and Signal Processing, CISP'09, October 17, 2009 - October 19, 2009, Tianjin, China
Luo T.; Zheng X.-F.; Ding T.-F.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

It needs to set the two thresholds of classical Canny Operator manually which confined this algorithm. A lot of research on adaptive thresholds choice method has been done to conquer this shortcoming. Based on the gradient histogram which is studied constantly in the past a method of gradient histogram difference diagram with adaptive image classification techniques is proposed in this paper. It automatically sets the two thresholds and avoids disconnected or false edges in detection. Experiments prove that the method is threshold-adaptive and the edge detection performs well in color image whose larger gradient amplitude pixels are mainly located in the edges between the target and background. 2009 IEEE.

Embedded system of image storage based on Fiber Channel (EI CONFERENCE) 会议论文 OAI收割
Quantum Optics, Optical Data Storage, and Advanced Microlithography, November 12, 2007 - November 14, 2007, Beijing, China
作者: Wang H.; Wang H.; Wang H.; Wang H.; Chen X.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

In domains of aerospace aviation aiming and optic measure etc. the embedded system of imaging processing and recording is absolutely necessary which has small volume high processing speed and high resolution. But the embedded storage technology becomes system bottleneck because of developing slowly. It is used to use RAID to promote storage speed but it is unsuitable for the embedded system because of its big volume. Fiber channel (FC) technology offers a new method to develop the high-speed portable storage system. In order to make storage subsystem meet the needs of high storage rate make use of powerful Virtex-4 FPGA and high speed fiber channel advance a project of embedded system of digital image storage based on Xilinx Fiber Channel Arbitrated Loop LogiCORE. This project utilizes Virtex4 RocketIO MGT transceivers to transmit the data serially and connects many Fiber Channel hard drivers by using of Arbitrated Loop optionally. It can achieve 400MBps storage rate breaks through the bottleneck of PCI interface and has excellences of high-speed real-time portable and massive capacity.

Intelligent MRTD testing for thermal imaging system using ANN (EI CONFERENCE) 会议论文 OAI收割
ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China
Sun J.; Ma D.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The Minimum Resolvable Temperature Difference (MRTD) is the most widely accepted figure for describing the performance of a thermal imaging system. Many models have been proposed to predict it. The MRTD testing is a psychophysical task for which biases are unavoidable. It requires laboratory conditions such as normal air condition and a constant temperature. It also needs expensive measuring equipments and takes a considerable period of time. Especially when measuring imagers of the same type the test is time consuming. So an automated and intelligent measurement method should be discussed. This paper adopts the concept of automated MRTD testing using boundary contour system and fuzzy ARTMAP but uses different methods. It describes an Automated MRTD Testing procedure basing on Back-Propagation Network. Firstly we use frame grabber to capture the 4-bar target image data. Then according to image gray scale we segment the image to get 4-bar place and extract feature vector representing the image characteristic and human detection ability. These feature sets along with known target visibility are used to train the ANN (Artificial Neural Networks). Actually it is a nonlinear classification (of input dimensions) of the image series using ANN. Our task is to justify if image is resolvable or uncertainty. Then the trained ANN will emulate observer performance in determining MRTD. This method can reduce the uncertainties between observers and long time dependent factors by standardization. This paper will introduce the feature extraction algorithm demonstrate the feasibility of the whole process and give the accuracy of MRTD measurement.

The compression and storage method of the same kind of medical images-DPCM (EI CONFERENCE) 会议论文 OAI收割
4th International Conference on Photonics and Imaging in Biology and Medicine, September 3, 2005 - September 6, 2005, Tianjin, China
作者: Liu H.; Liu H.; Liu H.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

Medical imaging has started to take advantage of digital technology opening the way for advanced medical imaging and teleradiology. Medical images however require large amounts of memory. At over 1 million bytes per image a typical hospital needs a staggering amount of memory storage (over one trillion bytes per year) and transmitting an image over a network (even the promised superhighway) could take minutes - too slow for interactive teleradiology. This calls for image compression to reduce significantly the amount of data needed to represent an image. Several compression techniques with different compression ratio have been developed. However the lossless techniques which allow for perfect reconstruction of the original images yield modest compression ratio while the techniques that yield higher compression ratio are lossy that is the original image is reconstructed only approximately Medical imaging poses the great challenge of having compression algorithms that are lossless (for diagnostic and legal reasons) and yet have high compression ratio for reduced storage and transmission time. To meet this challenge we are developing and studying some compression schemes which are either strictly lossless or diagnostically lossless taking advantage of the peculiarities of medical images and of the medical practice. In order to increase the Signal to-Noise Ratio (SNR) by exploitation of correlations within the source signal a method of combining differential pulse code modulation (DPCM) is presented.