Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729679
Zhenyi Luo, Wenyi Wang, Jiying Zhao, Yu Liu
In this paper, a novel matting method is proposed to automatically detect and separate foreground, background and transitional (unknown) regions in a color image. In order to detect the background color, K-means clustering in YCbCr color space is firstly used to classify the background colors into a limited number of clusters. Then the spatial information is further used to refine the background and minimize the unknown regions. In this case, an image can be automatically segmented into three hard regions: foreground, background and unknown regions. For transitional (unknown) regions, the alpha matting based on Wang's robust matting algorithm is utilized to refine the accuracy of the separation results. By combining an automatical background determination metric and Wang's robust matting, the proposed matting method can handle images with single-colored or gridded background. The required user input is significantly simplified compared to conventional alpha matting schemes which require users to provide a hard image segmentation manually. The experimental results show that improved matting results can be achieved for complex unknown regions which contain semi-transparent materials or tiny objects such as hair stripes.
{"title":"Color range determination and alpha matting for color images","authors":"Zhenyi Luo, Wenyi Wang, Jiying Zhao, Yu Liu","doi":"10.1109/IST.2013.6729679","DOIUrl":"https://doi.org/10.1109/IST.2013.6729679","url":null,"abstract":"In this paper, a novel matting method is proposed to automatically detect and separate foreground, background and transitional (unknown) regions in a color image. In order to detect the background color, K-means clustering in YCbCr color space is firstly used to classify the background colors into a limited number of clusters. Then the spatial information is further used to refine the background and minimize the unknown regions. In this case, an image can be automatically segmented into three hard regions: foreground, background and unknown regions. For transitional (unknown) regions, the alpha matting based on Wang's robust matting algorithm is utilized to refine the accuracy of the separation results. By combining an automatical background determination metric and Wang's robust matting, the proposed matting method can handle images with single-colored or gridded background. The required user input is significantly simplified compared to conventional alpha matting schemes which require users to provide a hard image segmentation manually. The experimental results show that improved matting results can be achieved for complex unknown regions which contain semi-transparent materials or tiny objects such as hair stripes.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127111206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729718
Fuqin Deng, Jianyang Liu, Jiangwen Deng, Kenneth S. M. Fung, E. Lam
Non-contact optical imaging system design and the corresponding surface profilometry algorithm are critical components in various metrology applications, such as surface inspection of semiconductor components on the production line. For such challenging industrial applications, the most important considerations are often automation, precision and speed of the inspection. In this work, we propose a mathematical framework and a dynamic phase-shift algorithm (D-PSA) for a dense surface profilometry of moving objects. We also present a fringe pattern projection system with projector and camera arrays, with an aim to reduce the undesirable effects such as the uneven illumination and the perspective geometry effect on the reconstructed surface using a large field-of-view inspection system. This system is then applied to the inspection of the surface of moving printed circuit boards along a conveyor belt. Experimental results show that our approach can reconstruct the object surface effectively and efficiently.
{"title":"A three-dimensional imaging system for surface profilometry of moving objects","authors":"Fuqin Deng, Jianyang Liu, Jiangwen Deng, Kenneth S. M. Fung, E. Lam","doi":"10.1109/IST.2013.6729718","DOIUrl":"https://doi.org/10.1109/IST.2013.6729718","url":null,"abstract":"Non-contact optical imaging system design and the corresponding surface profilometry algorithm are critical components in various metrology applications, such as surface inspection of semiconductor components on the production line. For such challenging industrial applications, the most important considerations are often automation, precision and speed of the inspection. In this work, we propose a mathematical framework and a dynamic phase-shift algorithm (D-PSA) for a dense surface profilometry of moving objects. We also present a fringe pattern projection system with projector and camera arrays, with an aim to reduce the undesirable effects such as the uneven illumination and the perspective geometry effect on the reconstructed surface using a large field-of-view inspection system. This system is then applied to the inspection of the surface of moving printed circuit boards along a conveyor belt. Experimental results show that our approach can reconstruct the object surface effectively and efficiently.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125969596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729706
Hamidreza Rabiei-Dastjerdi, M. Farrokhifar
One of the most crucial needs for every researcher who use statistical data at different scales specific at urban scale is designing and defining areal unit of analyses. Some experts use official zoning system and some other use a purpose-based areal units and new zoning system regarding their need and goals of the study. In a city or region, administrative zones are usually designed based on political and administrative intentions. Urban researchers study the city at different levels from local (neighborhood) to the global scale of the city. Here the modifiable areal unit problem shows up. One of the best functional solutions for MAUP problem is using Genetic Algorithm techniques Genetic algorithms (GA) are subclasses of Evolutionary Computing. This method can counter the effects of MAUP on spatial based statistical indexes and results. In this paper GA has been used for zone design and portioning city into proper districts for produced (objective) accessibility raster map in Tehran which is a practical real world problem. The GA accounts for essential characteristics population equality, contiguity, geographical compactness. The result shows significant improvements in the matters of easiness of application and fastness for Automated Zone Design (AZD) in real world problems also add some general concepts to show the benefits of our work for urban planners and spatial data researchers and analyzers who face the MAUP.
{"title":"Genetic algorithms solution to automated zone design based on urban population map","authors":"Hamidreza Rabiei-Dastjerdi, M. Farrokhifar","doi":"10.1109/IST.2013.6729706","DOIUrl":"https://doi.org/10.1109/IST.2013.6729706","url":null,"abstract":"One of the most crucial needs for every researcher who use statistical data at different scales specific at urban scale is designing and defining areal unit of analyses. Some experts use official zoning system and some other use a purpose-based areal units and new zoning system regarding their need and goals of the study. In a city or region, administrative zones are usually designed based on political and administrative intentions. Urban researchers study the city at different levels from local (neighborhood) to the global scale of the city. Here the modifiable areal unit problem shows up. One of the best functional solutions for MAUP problem is using Genetic Algorithm techniques Genetic algorithms (GA) are subclasses of Evolutionary Computing. This method can counter the effects of MAUP on spatial based statistical indexes and results. In this paper GA has been used for zone design and portioning city into proper districts for produced (objective) accessibility raster map in Tehran which is a practical real world problem. The GA accounts for essential characteristics population equality, contiguity, geographical compactness. The result shows significant improvements in the matters of easiness of application and fastness for Automated Zone Design (AZD) in real world problems also add some general concepts to show the benefits of our work for urban planners and spatial data researchers and analyzers who face the MAUP.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123298876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729731
Orestis Liolis, Vicky S. Kalogeiton, Dim P. Papadopoulos, G. Sirakoulis, V. Mardiris, A. Gasteratos
Non-linear morphological edge detectors have been proven to be robust in the presence of noise and able to discriminate between edges and regions corrupted by noise. In this paper a novel non-linear morphological edge detector is presented when implemented as a compact circuit on Quantum Cellular Automata (QCA) in crossbar nanoelectronic architecture. The proposed QCA implementation provides high circuit performance, very low dimensions, parallel processing and very low power consumption. Moreover, the presented QCA circuit design obeys with the QCA design rules while focusing on circuit functionality robustness and thereafter provides real time image processing. The corresponding simulation results indicate the efficiency of the proposed circuitry.
{"title":"Morphological edge detector implemented in Quantum Cellular Automata","authors":"Orestis Liolis, Vicky S. Kalogeiton, Dim P. Papadopoulos, G. Sirakoulis, V. Mardiris, A. Gasteratos","doi":"10.1109/IST.2013.6729731","DOIUrl":"https://doi.org/10.1109/IST.2013.6729731","url":null,"abstract":"Non-linear morphological edge detectors have been proven to be robust in the presence of noise and able to discriminate between edges and regions corrupted by noise. In this paper a novel non-linear morphological edge detector is presented when implemented as a compact circuit on Quantum Cellular Automata (QCA) in crossbar nanoelectronic architecture. The proposed QCA implementation provides high circuit performance, very low dimensions, parallel processing and very low power consumption. Moreover, the presented QCA circuit design obeys with the QCA design rules while focusing on circuit functionality robustness and thereafter provides real time image processing. The corresponding simulation results indicate the efficiency of the proposed circuitry.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117029834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729678
H. Ji, B. Jiang, Zhiyao Huang, Baoliang Wang, Haiqing Li
Based on image sequence, a void fraction measurement model of gas-liquid two-phase flow in mini-pipe is developed using support vector regression (SVR) and particle swarm optimization (PSO). A high-speed image acquisition system is constructed to capture dynamic gray image sequence of gas-liquid two-phase flow. The area ratio of gas phase in longitudinal section of the pipe for every image of image sequence is calculated and one-dimension time series can be obtained. And then the mean value, the standard deviation and the nonsymmetrical coefficient are extracted from the one-dimension time series as input vector of the void fraction measurement model. The experiment is carried out in the horizontal mini-pipe with inner diameter of 4.0mm. The results show that the presented void fraction measurement model is feasible and effective. The maximum relative errors of void fraction of slug flow and bubbly flow are less than 8%.
{"title":"Void fraction measurement of gas-liquid two-phase flow in mini-pipe based on image sequence","authors":"H. Ji, B. Jiang, Zhiyao Huang, Baoliang Wang, Haiqing Li","doi":"10.1109/IST.2013.6729678","DOIUrl":"https://doi.org/10.1109/IST.2013.6729678","url":null,"abstract":"Based on image sequence, a void fraction measurement model of gas-liquid two-phase flow in mini-pipe is developed using support vector regression (SVR) and particle swarm optimization (PSO). A high-speed image acquisition system is constructed to capture dynamic gray image sequence of gas-liquid two-phase flow. The area ratio of gas phase in longitudinal section of the pipe for every image of image sequence is calculated and one-dimension time series can be obtained. And then the mean value, the standard deviation and the nonsymmetrical coefficient are extracted from the one-dimension time series as input vector of the void fraction measurement model. The experiment is carried out in the horizontal mini-pipe with inner diameter of 4.0mm. The results show that the presented void fraction measurement model is feasible and effective. The maximum relative errors of void fraction of slug flow and bubbly flow are less than 8%.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114373365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729693
Berk Pelenk, T. Acarman
This paper presents a moving object tracking system with a Particle Filter algorithm. A software tool is developed to track an unknown moving object in a sensing region occupied by other dynamic objects. Several components are used to determine objects, to self-localize, and to match the determined objects iteratively in conjunction with the previously determined objects. Each object is labeled with a unique identification number. Main sensor is a Laser Imaging Detection and Ranging (LIDAR) to sense the objects, Inertial Measurement Unit (IMU) is used to localize the ego-vehicle and wheel odometer is used to improve the accuracy of positioning. The Particle Filter algorithm predicts self-position, utilizing the data received from both the IMU and the odometer. Performance and detection accuracy tests are carried out using various sized objects, as well as different environmental settings in order to conduct a comparison analysis for the gathered data.
{"title":"Object detection and tracking using sensor fusion and Particle Filter","authors":"Berk Pelenk, T. Acarman","doi":"10.1109/IST.2013.6729693","DOIUrl":"https://doi.org/10.1109/IST.2013.6729693","url":null,"abstract":"This paper presents a moving object tracking system with a Particle Filter algorithm. A software tool is developed to track an unknown moving object in a sensing region occupied by other dynamic objects. Several components are used to determine objects, to self-localize, and to match the determined objects iteratively in conjunction with the previously determined objects. Each object is labeled with a unique identification number. Main sensor is a Laser Imaging Detection and Ranging (LIDAR) to sense the objects, Inertial Measurement Unit (IMU) is used to localize the ego-vehicle and wheel odometer is used to improve the accuracy of positioning. The Particle Filter algorithm predicts self-position, utilizing the data received from both the IMU and the odometer. Performance and detection accuracy tests are carried out using various sized objects, as well as different environmental settings in order to conduct a comparison analysis for the gathered data.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124492963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729694
Bai Xueqiong, Li Lin
Researchers have made considerable progress in the development of Earth Observation (EO) technology since 1960s. EO satellites usually span a quite wide wave-band from visible to infrared light or even to microwave. In this paper, we propose an optical design on multi-waveband spaceborne EO system. The design scheme adopts a coaxial two-mirror optical system together, which is able to image into visible light, near-and mid-infrared light as well as hyper-spectral channels simultaneously by utilizing a beam split parallel glass plate. The initial configuration parameters of the system are resolved by the primary aberration theory. Then we optimize the aberration by ZEMAX, which is one of the most popular software of optical design in the world. The channels of mid-and near-infrared light make use of re-imaging method, which allows the exit pupil match with the cold baffle of detector. The primary mirror of this optical system is used for visible and infrared wavebands together whose aperture is 700mm. The visible field of view is 1.08°×1.08°, focal length is 6450mm; the mid-infrared field of view is 0.66°×0.66°, focal length is 1620mm; the near-infrared field of view is 0.34°×0.34°, focal length is 3310mm. Consequently, this optical design can combine visible light and infrared light together and shrink the weight and volume of the system, meanwhile guarantee the imaging quality to be always near to the diffraction limit.
{"title":"Optical design of spaceborne multi-waveband Earth Observation system","authors":"Bai Xueqiong, Li Lin","doi":"10.1109/IST.2013.6729694","DOIUrl":"https://doi.org/10.1109/IST.2013.6729694","url":null,"abstract":"Researchers have made considerable progress in the development of Earth Observation (EO) technology since 1960s. EO satellites usually span a quite wide wave-band from visible to infrared light or even to microwave. In this paper, we propose an optical design on multi-waveband spaceborne EO system. The design scheme adopts a coaxial two-mirror optical system together, which is able to image into visible light, near-and mid-infrared light as well as hyper-spectral channels simultaneously by utilizing a beam split parallel glass plate. The initial configuration parameters of the system are resolved by the primary aberration theory. Then we optimize the aberration by ZEMAX, which is one of the most popular software of optical design in the world. The channels of mid-and near-infrared light make use of re-imaging method, which allows the exit pupil match with the cold baffle of detector. The primary mirror of this optical system is used for visible and infrared wavebands together whose aperture is 700mm. The visible field of view is 1.08°×1.08°, focal length is 6450mm; the mid-infrared field of view is 0.66°×0.66°, focal length is 1620mm; the near-infrared field of view is 0.34°×0.34°, focal length is 3310mm. Consequently, this optical design can combine visible light and infrared light together and shrink the weight and volume of the system, meanwhile guarantee the imaging quality to be always near to the diffraction limit.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"386 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132979059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729668
M. Pastorino, M. Raffetto, A. Randazzo
An electromagnetic method is proposed for the retrieval of dielectric parameters and velocity profiles inside pipelines. It is based on the solution of an inverse scattering problem for cylindrical configurations. An axially moving multilayer elliptic cylinder is assumed. Relativistic velocities can be considered, too. The measurement of the field vectors is assumed to be performed around the cylinder in a given observation domain. The related inverse problem is formulated through series expansions in the spatial domain in which the dielectric properties and velocities of the various layers are the problem unknowns. The resulting equations are discretized and the obtained ill-posed algebraic system is recast as an optimization problem and solved by using the Artificial Bee Colony method, which is a stochastic optimization method. The paper includes an outline of the direct scattering formulation for the multilayer elliptic cylinder and a detailed description of the considered inverse problem. Several numerical results are reported in order to preliminary assess the capabilities and limitations of the proposed approach.
{"title":"Reconstruction of dielectric and velocity profiles in pipelines through an electromagnetic inverse scattering technique","authors":"M. Pastorino, M. Raffetto, A. Randazzo","doi":"10.1109/IST.2013.6729668","DOIUrl":"https://doi.org/10.1109/IST.2013.6729668","url":null,"abstract":"An electromagnetic method is proposed for the retrieval of dielectric parameters and velocity profiles inside pipelines. It is based on the solution of an inverse scattering problem for cylindrical configurations. An axially moving multilayer elliptic cylinder is assumed. Relativistic velocities can be considered, too. The measurement of the field vectors is assumed to be performed around the cylinder in a given observation domain. The related inverse problem is formulated through series expansions in the spatial domain in which the dielectric properties and velocities of the various layers are the problem unknowns. The resulting equations are discretized and the obtained ill-posed algebraic system is recast as an optimization problem and solved by using the Artificial Bee Colony method, which is a stochastic optimization method. The paper includes an outline of the direct scattering formulation for the multilayer elliptic cylinder and a detailed description of the considered inverse problem. Several numerical results are reported in order to preliminary assess the capabilities and limitations of the proposed approach.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"292 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134329058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729674
G. Giakos, A. Deshpande, T. Quang, T. Farrahi, C. Narayan, S. Shrestha, M. Zervakis, G. Livanos, E. Bei
An optical system for efficient fluorescence imaging of cancer margins aiming at enhanced discrimination of the tumor area from the surrounding normal tissue, is presented. Fluorescence imaging was used to acquire grayscale images of brain tumor samples of 10 μm slice thickness. The tumor cells are characterized as Gli36Δ5 cells expressing Green Fluorescent Protein (GFP). An image processing technique involving the clustering-based concept of Otsu segmentation was applied to enhance the contrast and difference between the tumor and the rest of the tissue for improved visualization of tumor margins. Edge detection was performed on these processed images to mark the boundaries of the tumor area. The fluorescence imaging results depict clear demarcation of tumor boundary and a substantial improvement of the contrast, post processing.
{"title":"An automated digital fluorescence imaging system of tumor margins using clustering-based image thresholding","authors":"G. Giakos, A. Deshpande, T. Quang, T. Farrahi, C. Narayan, S. Shrestha, M. Zervakis, G. Livanos, E. Bei","doi":"10.1109/IST.2013.6729674","DOIUrl":"https://doi.org/10.1109/IST.2013.6729674","url":null,"abstract":"An optical system for efficient fluorescence imaging of cancer margins aiming at enhanced discrimination of the tumor area from the surrounding normal tissue, is presented. Fluorescence imaging was used to acquire grayscale images of brain tumor samples of 10 μm slice thickness. The tumor cells are characterized as Gli36Δ5 cells expressing Green Fluorescent Protein (GFP). An image processing technique involving the clustering-based concept of Otsu segmentation was applied to enhance the contrast and difference between the tumor and the rest of the tissue for improved visualization of tumor margins. Edge detection was performed on these processed images to mark the boundaries of the tumor area. The fluorescence imaging results depict clear demarcation of tumor boundary and a substantial improvement of the contrast, post processing.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"26 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133077657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-01DOI: 10.1109/IST.2013.6729714
Liu Huawei, Lv Wei, Zhou Huaichun
In order to improve the quality of tomography reconstruction for ill-posed problems with limited projections, a new idea of fabricating virtual lines of sight which are consistent with, but not lineally dependent on, the measured lines of sight is proposed in this paper. Using a scheme of equilateral triangle plane meshes whose edge length equals twice the width of the lines of sight, based on the spatial continuity of the source term distribution, some independent virtual lines of sight are fabricated by an interpolation method described in this paper. Non-negative linear least squares method is used to solve the reconstruction problem. As the times of interpolation for virtual lines approach a critical level (it is 6 for the case in this paper) the condition number of the matrix of the forward problem drops obviously, indicating that the independent interpolation method may effectively overcome the `ill-posed-ness' of the problem. Accordingly, if the times of interpolation for virtual lines are less than the critical level, the shape of the assumed source distribution, obviously could not be reconstructed; as the times of interpolation become larger than the critical level, the shape of the assumed source distribution has been recovered visually. With 10 times of interpolation for virtual lines, most of the relative errors near the four peaks are below 10 %, thus the effectiveness of the interpolation method is reasonably verified. In addition, the reconstruction method has good noise immunity.
{"title":"Fabrication of independent virtual lines for reconstruction of 2D source distribution with high spatial resolution equal to that of limited projections","authors":"Liu Huawei, Lv Wei, Zhou Huaichun","doi":"10.1109/IST.2013.6729714","DOIUrl":"https://doi.org/10.1109/IST.2013.6729714","url":null,"abstract":"In order to improve the quality of tomography reconstruction for ill-posed problems with limited projections, a new idea of fabricating virtual lines of sight which are consistent with, but not lineally dependent on, the measured lines of sight is proposed in this paper. Using a scheme of equilateral triangle plane meshes whose edge length equals twice the width of the lines of sight, based on the spatial continuity of the source term distribution, some independent virtual lines of sight are fabricated by an interpolation method described in this paper. Non-negative linear least squares method is used to solve the reconstruction problem. As the times of interpolation for virtual lines approach a critical level (it is 6 for the case in this paper) the condition number of the matrix of the forward problem drops obviously, indicating that the independent interpolation method may effectively overcome the `ill-posed-ness' of the problem. Accordingly, if the times of interpolation for virtual lines are less than the critical level, the shape of the assumed source distribution, obviously could not be reconstructed; as the times of interpolation become larger than the critical level, the shape of the assumed source distribution has been recovered visually. With 10 times of interpolation for virtual lines, most of the relative errors near the four peaks are below 10 %, thus the effectiveness of the interpolation method is reasonably verified. In addition, the reconstruction method has good noise immunity.","PeriodicalId":448698,"journal":{"name":"2013 IEEE International Conference on Imaging Systems and Techniques (IST)","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131508672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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