Journals >Opto-Electronic Engineering
Contents
2014
Volume: 41 Issue 8
16 Article(s)
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Research Article
Study of Auto Focusing Technique of Micro-vision System
LI Huiguang, WANG Shuai, SHA Xiaopeng, SHAO Nuan, and LI Feng
In the research of the evaluation function, this paper firstly states the improvement Discrete Cosine Transform (DCT) algorithm and Small Univalve Segment Assimilating Nucleus (SUSAN) algorithm. Then, combining with the improved DCT algorithm and SUSAN algorithm, a new focusing evaluation algorithm has been presented. In the research of the evaluation function, this paper firstly states the improvement Discrete Cosine Transform (DCT) algorithm and Small Univalve Segment Assimilating Nucleus (SUSAN) algorithm. Then, combining with the improved DCT algorithm and SUSAN algorithm, a new focusing evaluation algorithm has been presented. New algorithm collects the respective advantages of frequency domain algorithm and spatial domain algorithm, which enable the focus curve to has a greatly improvement in unimodal, local extreme points and sensitivity. In the research of the focusing window, a new selection method is proposed on the basis of the importance of image sub-block. The new method regards the gradient rate as image sub-block importance factor. Then, put the image sub-block whose factor value is less than threshold as background sub-block and removed. Finally, after removing background sub-block image, treat the rest of part as the focusing window. The new selection method can achieve dynamic distinguishing between target area and background area..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 1 (2014)
A New 3D Visual Positioning Method of Eye-to-Hand Stereovision of Robot
HU Xiaoping, XIE Ke, and PENG Tao
3D visual positioning is very important in position-based visual servoing for robot, directly affecting the control precision of the system. According to the robot with eye-to-hand and stereovision system, a direct method of visual positioning is proposed based on base coordinate system. It utilizes the corresponding r3D visual positioning is very important in position-based visual servoing for robot, directly affecting the control precision of the system. According to the robot with eye-to-hand and stereovision system, a direct method of visual positioning is proposed based on base coordinate system. It utilizes the corresponding relation of point to epipolar to establish homogeneous linear equations, for getting the fundamental matrix contained the relationship of relative position of two cameras. According to the properties of fundamental matrix, it is decomposed into projection matrix of two cameras relative to the base coordinate system of robot, so the method can reconstruct in the base coordinate system directly by equations of lines determined by planes in space. The method is simple and easy to be realized and the related experiment compared the measured coordinates with the actual coordinates, which shows that accuracy and efficiency of the method..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 10 (2014)
3D Micro Topography Measurement Based on Spatial Frequency Domain Algorithm
XU Yongxiang, ZHANG Qianfang, LIU Songsong, and LIU Yi
White light interferometry for topography measurement can avoid phase uncertainty trouble which exists in laser interferometry. Spatial Frequency Domain Algorithm (FDA), based on white-light scan interferometry, has the advantage of insensitivity to noise and higher calculation accuracy compared with other methods. AppWhite light interferometry for topography measurement can avoid phase uncertainty trouble which exists in laser interferometry. Spatial Frequency Domain Algorithm (FDA), based on white-light scan interferometry, has the advantage of insensitivity to noise and higher calculation accuracy compared with other methods. Applying FDA, two white light scanning tests on the surface of a step-like sample are carried on with a Mirau typed scan interference microscope. Thus two stepped profile results are obtained, their step heights difference not exceeding 1 nm. Meantime, the same sample is also tested with a Zygo Newview 7200 profiler, both topography results agreeing with each other and step heights differing by 0.9 nm. Besides, data processing results also show that the chromatic dispersion higher than 2nd order is completely negligible when applying FDA..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 16 (2014)
The Application of the wMPS in Airplane Level Measurement
XUE Bin, ZHU Jigui, YANG Linghui, ZHAO Ziyue, and YE Shenghua
In view of the shortcomings of the traditional level measurement technique on airplanes, we apply the wMPS on the airplane level measurement, which keeps better measurement accuracy and makes measuring period reduce from one day to one hour. Besides, the effect of model application indicates that the wMPS, which has veIn view of the shortcomings of the traditional level measurement technique on airplanes, we apply the wMPS on the airplane level measurement, which keeps better measurement accuracy and makes measuring period reduce from one day to one hour. Besides, the effect of model application indicates that the wMPS, which has very extensive applied foreground, highly meets the demand of applications like large-scale measurement and assembly..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 22 (2014)
A New Phase Stabilization Method for Interference Fringe Projection Using Sinusoidal Phase Modulation
BO En, DUAN Fajie, FENG Fan, Lü Changrong, and FU Xiao
Among methods for measuring the surface profile based on fringe projection, temperature drift and vibration are the main factors which cause phase drift in fringes. To stabilize the fringe phase, peak detection has been used to simplify the process of phase extraction in the phase compensation system (PCS), and a phaseAmong methods for measuring the surface profile based on fringe projection, temperature drift and vibration are the main factors which cause phase drift in fringes. To stabilize the fringe phase, peak detection has been used to simplify the process of phase extraction in the phase compensation system (PCS), and a phase stabilization technique based on sinusoidal phase modulation (SPM) has been developed. The optical fiber arms are twined on the cylinder-shaped piezoelectric transition (PZT), and a sinusoidal drive signal has been injected into PZT to realize SPM. The fringe projection can be achieved by combing Mach-Zehnder interference and Young's interference, in which the beams are split by a 2×2 fiber coupler. The photo detector detects Michelson interference signal formed by two reflected beams on two fiber exit faces, and the phase shift is extracted in the phase compensation system. The Coordinated Rotation Digital Computer (CORDIC) is applied for the arcsine calculation, and then a compensation signal is generated and added to drive PZT to achieve a well phase stabilization performance. Experiments show that phase stability in fringes can be measured with a precision up to 5.5 mrad, and the phase shift caused by external disturbances have been well eliminated..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 27 (2014)
Design of an Omnimax Polarization-mode Measurement System
ZHANG Zhongshun, GAO Jun, WU Lianghai, and FAN Zhiguo
For the deficiencies of the existing polarization measurement system in the observation of Omnimax polarization mode, we build a full-sky imaging polarimeter system with full polarization measuring ability. The system is composed of fisheye lens, linear polarizer, quarter-wave retarder, macro lens, and CMOS camera, andFor the deficiencies of the existing polarization measurement system in the observation of Omnimax polarization mode, we build a full-sky imaging polarimeter system with full polarization measuring ability. The system is composed of fisheye lens, linear polarizer, quarter-wave retarder, macro lens, and CMOS camera, and presents some impressive measuring capabilities of nearly 180-degree field of view, full-polarization measurements and portable. We firstly introduce the system structure, working principle and optical design and the corresponding calibration method to obtain the system Muller matrix. System calibration makes the linear and circular polarization measurement errors less than 3% and 10%, respectively. Then, we obtain the full-sky skylight polarization patterns at the zenith at 488 nm band at the sunrise in the clear sky experiments. The experimental results are consistent with the theoretical value, which verifies the validity of the system in the Omnimax polarization characteristics observed..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 33 (2014)
Automatic Detection System of Optical Characteristic of Holographic Grating Used for Head-up Display
HONG Shaoxin, ZHANG Menghua, and ZHENG Jihong
To match the demand of fast detection of high quality holographic grating applied in head-up display, an automatically measuring and recording system is presented. The system is based on step rotation stages with high precision and LabView programming control technology. With this system, automatic measurement on severTo match the demand of fast detection of high quality holographic grating applied in head-up display, an automatically measuring and recording system is presented. The system is based on step rotation stages with high precision and LabView programming control technology. With this system, automatic measurement on several optical characteristics of transmission phase holographic gratings can be achieved. With different wavelengths and the whole 360 incident angles, the investigation on transmission changing of the holographic grating and analysis on the diffraction characteristics of the holographic grating could be used to optimize the fabrication method on the diffraction efficiency of the holographic grating. Holographic grating 360° measuring set-up helps to figure out how to arrange holographic grating in head-up display as a data base support..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 40 (2014)
Infrared Image Super-resolution Reconstruction
Based on Just Noticeable Difference
DAI Shaosheng, LIU Jinsong, DU Zhihui, XIANG Haiyan, and HU Yunqi
In order to avoid these disadvantages like poor contrast, low signal-to-noise ratio, and blurry visual effect of infrared images reconstructed using the existing super-resolution image reconstruction methods, an improved reconstruction algorithm of infrared images is proposed based on human visual system. The algorithmIn order to avoid these disadvantages like poor contrast, low signal-to-noise ratio, and blurry visual effect of infrared images reconstructed using the existing super-resolution image reconstruction methods, an improved reconstruction algorithm of infrared images is proposed based on human visual system. The algorithm introduces the contrast as prior information to reconstruct infrared images based on just noticeable difference, which projects objects interested to the ranges where human eyes are sensitive. Then create a measurement factor to distinguish project points and noise points to enhance the edge information of objects and filter noises. It is concluded from experimental results that the contrast of infrared images reconstructed has increased to double as the original value and the noise is eliminated. Visual effects of images obtained by the new method are improved dramatically..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 45 (2014)
Registration of SPECT Image and B-type Ultrasound Image Based on Artificial Bee Colony Algorithm
ZHENG Wei, GUO Lili, ZHAO Longfei, LIANG Zeng, and HAO Dongmei
In order to improve the accuracy in thyroid tumor detection, a registration of SPECT image and B-type ultrasound image based on artificial bee colony algorithm is improved. First, NSCT-GCBAC segmentation and KFCM segmentation are used respectively to extract the contours, according to the different characteristics of tIn order to improve the accuracy in thyroid tumor detection, a registration of SPECT image and B-type ultrasound image based on artificial bee colony algorithm is improved. First, NSCT-GCBAC segmentation and KFCM segmentation are used respectively to extract the contours, according to the different characteristics of thyroid SPECT image and B-type ultrasound image from two imaging devices. Second, mutual information is used for similarity measure, and affine transform model is adopted to solve the space transform parameters. Finally, an improved artificial bee colony algorithm is used to optimize the space registration transform parameters. The experimental results show that the method can effectively improve the speed and the effect of registration..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 51 (2014)
An Optimized SIFT Matching Based on RANSAC
ZHAO Ye, JIANG Jianguo, and HONG Richang
An improved SIFT method is proposed. Firstly, the step of describing key points changes the rectangular region of the descriptor into a circular region. By calculating the weighted gradient orientation histogram for each partitioning, a descriptor with 96 dimensions is composed. Secondly, we emphasize that a smaller neAn improved SIFT method is proposed. Firstly, the step of describing key points changes the rectangular region of the descriptor into a circular region. By calculating the weighted gradient orientation histogram for each partitioning, a descriptor with 96 dimensions is composed. Secondly, we emphasize that a smaller nearest neighbor ratio threshold leads to a highly accurate matching probability for the matched point but yields a low number of matching points. The matching points are ranked by the distance threshold of the nearest neighbor to the second nearest neighbor. We finally simplify RANSAC by establishing a new dataset based on the optimal matched points. The experimental results demonstrate that our approach enhances computation efficiency (about 10 times) and slightly improves accuracy than other algorithm. When the matching feature points increases, our method has more advantages in matching speed and higher matching accuracy than RANSAC-SIFT..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 58 (2014)
The Application of Improved KNN Algorithm in Optical Image Key Events Assessment
CHEN Shuaijun, JIANG Ping, and WU Qinzhang
KNN algorithm is a commonly used algorithm in the assessment of optical image key event. However, classical KNN algorithm always makes conclusion unreasonable, because it only concerns about the number of candidate cases, neglecting of candidate cases’ private characters. To solve this problem, an improved KNN algorithKNN algorithm is a commonly used algorithm in the assessment of optical image key event. However, classical KNN algorithm always makes conclusion unreasonable, because it only concerns about the number of candidate cases, neglecting of candidate cases’ private characters. To solve this problem, an improved KNN algorithm was proposed, which focused on the private characters of candidate cases. This paper argued that, the distance between candidate cases and target case, and the probability distribution of the candidate cases, both had important influence on last conclusion of target case. The test results showed that, the KNN algorithm proposed was more accurate than classical KNN algorithm, and the membership in proposed KNN algorithm represented degree of success or failure, which were more practical and more reasonable in the engineering practice..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 66 (2014)
P-N Semi-supervised Learning of Mutual Information Image Stabilization
WANG Hong
For dither video sequences in the tracking, detecting, combating situations, the observed target blurred, which is not conducive to the dynamics of the tracked target identification. This paper presents a semi-supervised learning mutual information entropy PN image stabilization algorithm to enhance the ability to jittFor dither video sequences in the tracking, detecting, combating situations, the observed target blurred, which is not conducive to the dynamics of the tracked target identification. This paper presents a semi-supervised learning mutual information entropy PN image stabilization algorithm to enhance the ability to jitter frequency video sequences, and reduce motion estimation error rate. PN semi-supervised learning of mutual information image stabilization is based on mutual information entropy theory for image motion estimation, on this basis, build parameters and jitter parameters is observed for motion compensation loop structure. Through the motion compensation parameters, semi-supervised PN learning are observed and performed. Mutual information entropy key parameters are corrected to ensure motion-compensated inter-frame parameter estimates and the actual amount of image jitter error is minimized and the output stability. By using mutual information entropy P-N learning semi-supervised learning algorithm for mutual information entropy image library jitter test comparison, motion estimation error rate reduced to 1%, to further enhance the ability of video sequences de-jitter frequency..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 73 (2014)
High Uniform Long Working Depth Laser Shaping System Design
YU Jinqing, YIN Shaoyun, YIN Zhiyong, DONG Xiaochun, SUN Xiuhui, GOU Jian, and DU Chunlei
High power solid state laser has strict requirements in the incident pump light. This paper reshape the beam of semiconductor laser array to a long working depth high uniform spot by combining microlens array and long focal depth Fresnel lens. A simulation system is designed, the input is from dilas E15Y-808.3-1260C laHigh power solid state laser has strict requirements in the incident pump light. This paper reshape the beam of semiconductor laser array to a long working depth high uniform spot by combining microlens array and long focal depth Fresnel lens. A simulation system is designed, the input is from dilas E15Y-808.3-1260C laser array, and the final spot is 4mm × 4mm. The result show that compared with conventional system, the working depth is 2 times extended and the uniformity in work depth maintains the same. The design is useful and effective, and provides a feasible way to high power semiconductor laser array pumping source..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 80 (2014)
Design of Optical System for a Static Ultraviolet Earth Simulator
XU Da, ZHANG Guoyu, and SUN Gaofei
Static ultraviolet earth simulator is a ground calibration and accuracy testing device for ultraviolet Navigation sensor. Ultraviolet earth simulator is a new type of earth simulator with small volume, high precision. This paper introduces an optical system for a static ultraviolet earth simulator and analyzes its paraStatic ultraviolet earth simulator is a ground calibration and accuracy testing device for ultraviolet Navigation sensor. Ultraviolet earth simulator is a new type of earth simulator with small volume, high precision. This paper introduces an optical system for a static ultraviolet earth simulator and analyzes its parameters. An optical system of static ultraviolet earth simulator with wide field of view is presented. It is composed of seven lenses. Its aperture, focal length, and field of view are respectively 10 mm, 100 mm, and Φ40°. Its distortion is less than 0.036%, its MTF value at Nyquist frequency of 50 lp/mm is higher than 0.7, RMS of its wavefront error is less than 0.037λ, and the earth angular error is less than 0.006 7°. The high precision index requirement is achieved and the imaging analysis results show that the design is a feasible scheme..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 85 (2014)
The Influence of Different Coating Process on Density Neutrality of Deep Attenuation Ni-Cr Film
WANG Zhonglian, WANG Ruisheng, YIN Xiaojun, ZHANG Yongxi, JIN Xiu, and MA Jing
Compare the density neutrality of Neutral Density (ND) filter coated with different coating process when the coating material is Ni80-Cr20. The density neutrality value is 3.7% when the filter coated with magnetron sputtering technical, and the value is better than that of coated with Electronic Beam(EB) evaporation orCompare the density neutrality of Neutral Density (ND) filter coated with different coating process when the coating material is Ni80-Cr20. The density neutrality value is 3.7% when the filter coated with magnetron sputtering technical, and the value is better than that of coated with Electronic Beam(EB) evaporation or resistance evaporation process, which valued 15%. Based on phase equilibrium theory, the reason why neutrality was reduced when coating Ni-Cr alloy under EB and resistance coatings were simulated and analyzed. At first of evaporation process, Cr is 2.8 times more than Ni, which causes density neutrality reduced. To certificate the analyzed results, Ni and Cr determination in both magnetron sputtering coating and resistance evaporation process were tested by Zeiss SEM and Oxford EDS. The experimental data is similar to theoretical results..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 8, 90 (2014)
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