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Features extraction and matching of teeth image based on the SIFT algorithm (EI CONFERENCE) 会议论文  OAI收割
2012 2nd International Conference on Computer Application and System Modeling, ICCASM 2012, July 27, 2012 - July 29, 2012, Shenyang, China
作者:  
Wang X.;  Wang X.;  Wang X.
收藏  |  浏览/下载:51/0  |  提交时间:2013/03/25
Using of SIFT algorithm in the image of teeth model  can detect the features of the teeth image effectively. In this approach  first  search over all scales and image locations by using a difference-of-Gaussian function to identify potential interest points that are invariant to scale and orientation. Second  select keypoints based on measures of their stability and a detailed model is fit to determine location and scale at each candidate location. Third  assign one or more orientations to each keypoint location based on local image gradient directions. Last  measure the local image gradients at the selected scale in the region around each keypoint. And then use the KNN algorithm to match the features. Through lots of experiments and comparing with other feature extraction methods  this method can detect the features of the teeth model effectively  and offer some available parameters for 3D reconstruction of the teeth model. the authors.  
A Low Complexity Switched Method for Enhancement of Spatial Resolution of Images 会议论文  OAI收割
International Conference on Materials Science and Information Technology (MSIT 2011)
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收藏  |  浏览/下载:30/0  |  提交时间:2016/06/04
The sequence measurement system of the IR camera (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者:  
Zhang H.-B.;  Han H.-X.;  Geng A.-H.
收藏  |  浏览/下载:57/0  |  提交时间:2013/03/25
Currently  the IR cameras are broadly used in the optic-electronic tracking  optic-electronic measuring  fire control and optic-electronic countermeasure field  but the output sequence of the most presently applied IR cameras in the project is complex and the giving sequence documents from the leave factory are not detailed. Aiming at the requirement that the continuous image transmission and image procession system need the detailed sequence of the IR cameras  the sequence measurement system of the IR camera is designed  and the detailed sequence measurement way of the applied IR camera is carried out. The FPGA programming combined with the SignalTap online observation way has been applied in the sequence measurement system  and the precise sequence of the IR camera's output signal has been achieved  the detailed document of the IR camera has been supplied to the continuous image transmission system  image processing system and etc. The sequence measurement system of the IR camera includes CameraLink input interface part  LVDS input interface part  FPGA part  CameraLink output interface part and etc  thereinto the FPGA part is the key composed part in the sequence measurement system. Both the video signal of the CmaeraLink style and the video signal of LVDS style can be accepted by the sequence measurement system  and because the image processing card and image memory card always use the CameraLink interface as its input interface style  the output signal style of the sequence measurement system has been designed into CameraLink interface. The sequence measurement system does the IR camera's sequence measurement work and meanwhile does the interface transmission work to some cameras. Inside the FPGA of the sequence measurement system  the sequence measurement program  the pixel clock modification  the SignalTap file configuration and the SignalTap online observation has been integrated to realize the precise measurement to the IR camera. Te sequence measurement program written by the verilog language combining the SignalTap tool on line observation can count the line numbers in one frame  pixel numbers in one line and meanwhile account the line offset and row offset of the image. Aiming at the complex sequence of the IR camera's output signal  the sequence measurement system of the IR camera accurately measures the sequence of the project applied camera  supplies the detailed sequence document to the continuous system such as image processing system and image transmission system and gives out the concrete parameters of the fval  lval  pixclk  line offset and row offset. The experiment shows that the sequence measurement system of the IR camera can get the precise sequence measurement result and works stably  laying foundation for the continuous system. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
Design of ground-based physical simulation system for satellite-borne TDI-CCD dynamic imaging (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者:  
Zhang L.;  Zhang L.;  Sun Z.
收藏  |  浏览/下载:41/0  |  提交时间:2013/03/25
As we know  the existence of image motion has a bad effect on the image quality of satellite-borne TDI CCD camera. Although many theories on image motion are proposed to cope with this problem  few simulations are done to justify the proposed theories on ground. And thus  in this paper  a ground-based physical simulation system for TDI CCD imaging is developed and specified  which consists of a physical simulation subsystem for precise satellite attitude control based on a 3-axis air bearing table  and an imaging and simulation subsystem utilizing area-array CCD to simulate TDI CCD. The designed system could realize not only a precise simulation of satellite attitude control  whose point accuracy is above 0.1 and steady accuracy above 0.01/s  but also an imaging simulation of 16-stage TDI CCD with 0.1s its integration time. This paper also gives a mathematical model of image motion of this system analogous with satellite-borne TDI CCD  and detailed descriptions on the principle utilizing area-array CCD to simulate TDI CCD. It is shown that experiment results are in accordance with mathematical simulation  and that the image quality deteriorate seriously when the correspondence between the image velocity and signal charges transfer velocity is broken out  which suggest not only the validity of the system design but also the validity of the proposed image motion theory of TDI CCD. 2010 SPIE.  
Modulation transfer function measurement technique for image sensor arrays (EI CONFERENCE) 会议论文  OAI收割
6th International Symposium on Precision Engineering Measurements and Instrumentation, August 8, 2010 - August 11, 2010, Hangzhou, China
作者:  
Jiang H.
收藏  |  浏览/下载:36/0  |  提交时间:2013/03/25
Restoration of an atmospherically blurred image based on physical model fusion approach (EI CONFERENCE) 会议论文  OAI收割
2010 IEEE 10th International Conference on Signal Processing, ICSP2010, October 24, 2010 - October 28, 2010, Beijing, China
作者:  
Wang Y.;  Li J.;  Li J.;  Li J.;  Wang Y.
收藏  |  浏览/下载:51/0  |  提交时间:2013/03/25
This paper proposes a new restoration method  only using the single image information  combining atmospheric physical model with fusion techniques to reduce the degradation of the image contrast in bad weather conditions caused by atmospheric aerosols  such as haze and fog. The basic idea of this method is to utilize physics-based model method instead of multisensors to generate a serial of virtual images  and then to fuse those virtual images into a high contrast image based on the wavelet fusion technique. In contrast to previous methods  our restoration technique is not only independent on predicted structure  distributions of scene reflectance  or detailed knowledge about the particular weather condition  but also adapt to the situation without a reference image or images with moving objects captured by a video camera. Experiments on different poorcontrast images demonstrate the availability of the proposed method in case of restoring the atmospherically blurred images. 2010 IEEE.  
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.
收藏  |  浏览/下载:89/0  |  提交时间:2013/03/25
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  
The methodology of detailed vegetation classification based on environmental knowledge and remote sensing images 会议论文  OAI收割
Xu Z. G.; Zhuang D. F.; Ieee
收藏  |  浏览/下载:29/0  |  提交时间:2012/06/30
Restoration of moving blurred image based on TMS320C6416 (EI CONFERENCE) 会议论文  OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Liu W.
收藏  |  浏览/下载:59/0  |  提交时间:2013/03/25
To absolve image blur caused by camera's high speed  fixed-point DSP TMS320C6416 and wiener filtering algorithm are adopted to stabilize image. On the premise that cameras have uniform motion  restoration model for moving blurred image was researched  the principle of Wiener filtering is explained  the key technologies of moving blurred image restoration with TMS320C6416 are introduced: how to complete FFT calculation of 32bit and how to exert DMA function of DSP to enhance processing speed  ring effect and ghost effect in restored image are explained  and how the parameter of wiener filter affects ring effect and ghost effect is discussed  in addition to this  other reasons of ring effect and ghost effect are analyzed detailed. Experiments shows that One TMS320C6416 chip can restore seven frames per second  there is great hope to realize real-time restoration if adopting multi-DSP or the FFT completion by hardware.