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Optimization of focusing position in laser induced breakdown spectroscopy system based on quantitative analysis internal standard method of steel 会议论文  OAI收割
Kunming, China, 2021-12-07
作者:  
Li, Zhicong;  Yang, Jianfeng;  Wang, Zhiyuan;  Zhao, Yiyi;  Huang, Shuaidong
  |  收藏  |  浏览/下载:47/0  |  提交时间:2022/04/27
Processing corrective focus and information focus at different positions: an electrophysiological investigation 期刊论文  OAI收割
LANGUAGE COGNITION AND NEUROSCIENCE, 2019, 卷号: 34, 期号: 8, 页码: 1059-1072
作者:  
Zheng, Z. L.;  Yang, X. H.;  Li, W. J.
  |  收藏  |  浏览/下载:73/0  |  提交时间:2019/09/10
Data normalization of single camera visual measurement network system (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Information Technology and Management Innovation, ICITMI 2012, November 10, 2012 - November 11, 2012, Guangzhou, China
作者:  
Zhang Y.-C.;  Zhou J.
收藏  |  浏览/下载:23/0  |  提交时间:2013/03/25
With the development of visual measurement system  Normalize the measured coordinates into the same world coordinate system  Apply in the three coordinate measuring machine(CMM) to have the simulation experiment  So the data normalization has the advantage of more high precision. (2013) Trans Tech Publications  the visual measurement system of single camera which applied in the imaging theory of optical feature points  then get the global data  the result indicates that the maximum absolute tolerance between the normalization coordinates via the center of point set and the ones measured by CMM directly is 0.058mm  Switzerland.  it has been widespread used in the modern production. Due to the limit of the environment in scene  and achieve the overall measurement  the visual measurement system of single camera could not measure the shield between the measured objects each other. Focus on this problem  But the one between the coordinate repeatedly measured at the position of one network control point is 0.066mm  present a kind of the the knowledge of measurement network based on the visual measurement of single camera  set up the measurement network system via the multi-control points. Measure the optical feature points in every network control point via the visual measurement system of single camera  
Study on Misalignment of Focus Position in Laser Metal Deposition Shaping Processing 会议论文  OAI收割
7th International Conference on e-Engineering and Digital Enterprise Technology, Shenyang, China, September 3-5, 2009
作者:  
Tian FJ(田凤杰);  Liu WJ(刘伟军);  Shang XF(尚晓峰);  Yang G(杨光)
收藏  |  浏览/下载:20/0  |  提交时间:2012/06/06
The effect on tolerance distributing of an off-axis three mirror anastigmatic optical system with wavefront coding technology (EI CONFERENCE) 会议论文  OAI收割
Optical System Alignment and Tolerancing II, August 10, 2008 - August 11, 2008, San Diego, CA, United states
作者:  
Yan F.;  Zhang X.-J.;  Yan F.
收藏  |  浏览/下载:34/0  |  提交时间:2013/03/25
The wavefront coding technology is known as a system-level technology which can extend the depth of focus of optical system by innovative optical design and image restoration. This technology can control misfocus related aberrations including misfocus  astigmatism  and Petzval curvature  temperature-related misfocus in digital imaging systems. It can also help optical system tolerate more residual error in optical manufacturing and alignment besides misfocus. The brief introduction of wavefront coding technology and the wavefront coded TMA system under research is presented respectively in part 1 and part 2. The "MTF similarity" is defined to describe the relationship among MTF at different position or different fields in the third part. It is also shown in this part that the MTF similarity of wavefront coded system is much higher than the normal system within a large range. In part 4 comparison between the origin system and the new system with wavefront coding technology is provided after multiple errors are introduced  from which it can be observed that the system with wavefront coding technology can tolerate much bigger error than origin system. The error tolerance is re-distributed according to a new criterion based on MTF similarity. If the MTF similarity is less than a certain value  it can be regarded that the system can tolerate the residual error. The new error tolerance is displayed and it is shown that the wavefront coding technology can also loosen the error distributing besides extended the depth of focus.  
Autofocusing technique based on image processing for remote-sensing camera (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2007 - Image Processing, September 9, 2007 - September 12, 2007, Beijing, China
作者:  
Wang X.;  Xu S.-Y.;  Wang X.;  Wang X.
收藏  |  浏览/下载:20/0  |  提交时间:2013/03/25
The key to the auto-focusing technique based on image processing is the selection of focus measure reflecting image definition. Usually the measures derived are on the premise of the images acquired with the same scene. As for the remote-sensing camera working in linear CCD push-broom imaging mode  the premise doesn't exist because the scenes shot are different at any moment  which brings about difficulties to the selection of the focus measure. To evaluate the image definition  the focus measure based on blur estimation for rough adjustment is proposed to estimate the focused position by only two different lens positions  which greatly saves the auto-focusing time. Another evaluation function based on edge sharpness is developed to find best imaging position in the narrow range. Simulations show that the combination of the two measures has the advantages of rapid reaction and high accuracy.  
High-accuracy real-time automatic thresholding for centroid tracker (EI CONFERENCE) 会议论文  OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Wang Y.;  Wang Y.;  Wang Y.;  Wang Y.;  Zhang Y.
收藏  |  浏览/下载:37/0  |  提交时间:2013/03/25
Many of the video image trackers today use the centroid as the tracking point. In engineering  we can get several key pairs of peaks which can include the target and the background around it and use the method of Otsu to get intensity thresholds from them. According to the thresholds  it give a great help for us to get a glancing size  a target's centroid is computed from a binary image to reduce the processing time. Hence thresholding of gray level image to binary image is a decisive step in centroid tracking. How to choose the feat thresholds in clutter is still an intractability problem unsolved today. This paper introduces a high-accuracy real-time automatic thresholding method for centroid tracker. It works well for variety types of target tracking in clutter. The core of this method is to get the entire information contained in the histogram  we can gain the binary image and get the centroid from it. To track the target  so that we can compare the size of the object in the current frame with the former. If the change is little  such as the number of the peaks  the paper also suggests subjoining an eyeshot-window  we consider the object has been tracked well. Otherwise  their height  just like our eyes focus on a target  if the change is bigger than usual  position and other properties in the histogram. Combine with this histogram analysis  we will not miss it unless it is out of our eyeshot  we should analyze the inflection in the histogram to find out what happened to the object. In general  the impression will help us to extract the target in clutter and track it and we will wait its emergence since it has been covered. To obtain the impression  what we have to do is turning the analysis into codes for the tracker to determine a feat threshold. The paper will show the steps in detail. The paper also discusses the hardware architecture which can meet the speed requirement.  the paper offers a idea comes from the method of Snakes  
Image deconvolution in spherical aberration-corrected high-resolution transmission electron microscopy 期刊论文  OAI收割
ULTRAMICROSCOPY, 2006, 卷号: 106, 期号: 6, 页码: 539
Tang, CY; Chen, JH; Zandbergen, HW; Li, FH
收藏  |  浏览/下载:28/0  |  提交时间:2013/09/17
Self Imaging technique for refocusing an aerospace camera (EI CONFERENCE) 会议论文  OAI收割
ICO20: Optical Devices and Instruments, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Li W.;  Li W.;  Wang X.;  Wang X.;  Wang X.
收藏  |  浏览/下载:33/0  |  提交时间:2013/03/25
A novel auto-focusing technique using a self imaging approach is developed for an aerospace camera having large aperture and long focus. Its optical system consists of an emitting system  receiving system  and two penta-prisms. Emitting system has three parts: a light source  beamsplitter  and aim slit. The receiving system includes a field lens  two separate lenses  and CCD. Using two little penta-prisms instead of a large planar mirror makes the autofocus system simple and compact. CCD was used as photoelectric converting device. A defocused signal is acquired by measuring the change of the two slit self-images position imaged on the CCD. A simple and compact construction of the auto-focusing system was proposed. The algorithm to calculate the moving of the slit-self images position was analyzed in order to achieve subpixel position estimation. The results of the experiments show a 10m focusing precision. The system demonstrates high resolution  easy adjustment and high reliability.