2011
2011
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Record 121 of
Title:Color image segmentation based on mean shift mode seeking
Author(s):Ma, Junyong(1,2); Wen, Desheng(1); Yang, Shaodong(1,2); Xu, Zhigang(1,2)Source: Journal of Computational Information Systems Volume: 7 Issue: 12 DOI: Published: December 2011Abstract:Extracting the salient regions from images plays an important role in image understanding, computer vision, pattern recognition and so on. This paper presents a color image segmentation method based on mean shift clustering to pave the way for identifying the salient objects in an image. As a widely used clustering method for segmentation, mean shift can automatically seek the modes of the underlying probability density function of an image. However, mean shift used in L*a*b* color space often results in over-segmentation. In our segmentation scheme, we choose only color information of L*a*b* color space and employ the mean shift procedures to determine all cluster centroids. Then every pixel is allocated into the cluster whose cluster centroid is closest to that pixel. To demonstrate the effectiveness of the proposed scheme, we apply it to classifying synthetic images and segmenting natural images. Excellent segmentation results have been obtained and it is concluded that the proposed segmentation method can overcome the problem of over-segmentation and make a big step toward the salient regions extraction. Copyright ? 2011 Binary Information Press.Accession Number: 20115014598387 -
Record 122 of
Title:Medium-sized aperture deployable telescope for microsatellite application
Author(s):Feng, Xuegui(1,2); Li, Chuang(1); Ren, Guorui(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8196 Issue: DOI: 10.1117/12.901038 Published: 2011Abstract:An important research interest on space optics is the ultra-light space telescope technology which is compatible with microsatellite platform. To realize lightweight telescope, one way is to develop deployable telescopes. They not only maintain the capabilities of traditional non-deployable telescopes but also have compacter launch volume and lighter weight and lower cost. We investigate the telescope with accurate deployable structure based on tape springs. Before launch, the secondary mirror support structure with tape springs is folded, and when the satellite is on orbit, the secondary mirror is deployed with the elastic strain energy of folded tape springs. There are mainly three parts in the paper. Firstly, the telescope optics was presented. A Ritchey-Chretien (RC) type optical system with 300mm aperture was designed. The influence of the secondary mirror misalignment on the optical performance was analyzed. Secondly, the deployable telescope structure with tape springs was designed for the RC system. The finite element method (FEM) was used to analysis the dynamics of the unfolded telescope structure. Finally, the deployment precision metering system was discussed. ? 2011 SPIE.Accession Number: 20113614296295 -
Record 123 of
Title:Movement analysis of nano-magnetic-particles in a magnetic fluid using laser speckle shearing technology
Author(s):Wang, Xi-Jun(1); Wang, Ya-Jun(2)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 19 Issue: 7 SUPPL. DOI: 10.3788/OPE.20111913.0400 Published: July 2011Abstract:In order to analyze the movement of nano-magnetic particles in the magnetic fluid, a double-beam speckle shearing interference device was designed. The working principles of the speckle shearing interference device was introduced and the movement of magnetic particles in nanometer dimensions was researched by the proposed device. A dynamic speckle time series image of the magnetic particles was obtained. On the basis of imaging dividing, the correlation coefficient of the image and lateral displacements of the magnetic particles were calculated. It shows that the resolution of lateral displacement has been 1 μm. The results indicate that the double beam speckle shearing system is a more efficient way to study the movement of namo-magnetic particles.Accession Number: 20114614525026 -
Record 124 of
Title:A novel alternative algorithm for limited angle tomography
Author(s):Lu, Xiaoqiang(1); Yuan, Yuan(1); Yan, Pingkun(1); Li, Xuelong(1)Source: Proceedings - International Conference on Image Processing, ICIP Volume: Issue: DOI: 10.1109/ICIP.2011.6116536 Published: 2011Abstract:This paper studies incomplete data problems of circular cone-beam computed tomography, which occur frequently in medical imaging and industrial imaging. The incomplete data problems in which projection data are only available in an angular range can be attributed to the limited angle tomography. Limited angle tomography is a severely ill-posed inverse problem. In recent years, image reconstruction based on total variation (TV) was employed to reduce the problem and gave better performance on edge-preserving reconstruction. However, the artificial parameter can only be determined through considerable experimentation. In this paper, an alternating minimization method based on TV is proposed to reduce the data insufficiency in tomographic imaging. This novel alternating minimization method provides a robust and effective reconstruction without any artificial parameter in the iterative processes, by using the TV as a multiplicative constraint. The results demonstrate that this new reconstruction method brings satisfactory performance. ? 2011 IEEE.Accession Number: 20120514730566 -
Record 125 of
Title:Compressed hyperspectral image sensing reconstruction based on interband prediction and joint optimization
Author(s):Liu, Hai-Ying(1); Wu, Cheng-Ke(1); Lü, Pei(2); Song, Juan(1)Source: Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology Volume: 33 Issue: 9 DOI: 10.3724/SP.J.1146.2010.01343 Published: September 2011Abstract:According to the correlation analysis of Compressed Sensing (CS) measurements for hyperspectral images, a new reconstruction algorithm based on interband prediction and joint optimization is proposed. In the method, linear prediction is first applied to remove the correlations among successive hyperspectral measurement vectors. The obtained residual measurement vectors are then recovered using the proposed joint optimization based POCS (Projections Onto Convex Sets) algorithm with the steepest descent method. In addition, a pixel-guided stopping criterion is introduced to stop the iteration. Experimental results show that the proposed algorithm exhibits its superiority over other known CS reconstruction algorithms in the literature at the same measurement rates, while with a faster convergence speed.Accession Number: 20114214431743 -
Record 126 of
Title:Deployment precision measurement modeling of a deployable space telescope based on tape springs
Author(s):Li, Chuang(1); Feng, Xuegui(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8321 Issue: DOI: 10.1117/12.905134 Published: 2011Abstract:Tape springs have many advantages to develop spaced-based deployable systems because of their simple structures, light weights, high stiffness, and the abilities of self-deploy and self-lock. Their applications in deployable space structures make the spaced-based systems fulfill the requirements of light weight and compact launching volume. A new kind of deployable space telescope under research uses tape springs as the support structure of secondary mirror. Before launch, the support structure of secondary mirror is folded, and deployed when on orbit. In order to achieve near diffraction limited imaging quality, the deployment precision must reach the level consistent with the optical compensation system. We designed an accurate measuring system based on position sensitive detectors (PSDs) to measure the deployment precision. The measuring system includes 3 laser diodes, 3 two-dimensional PSDs around the primary mirror of the deployable telescope, and 3 small mirrors around the secondary mirror. The equations linking the PSD readings and the six-degree-of-freedom displacement of the secondary mirror were deduced. With these equations, the deployment errors can be resolved. ? 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Accession Number: 20120114664525 -
Record 127 of
Title:Learning shape statistics for hierarchical 3D medical image segmentation
Author(s):Zhang, Wuxia(1); Yuan, Yuan(1); Li, Xuelong(1); Yan, Pingkun(1)Source: Proceedings - International Conference on Image Processing, ICIP Volume: Issue: DOI: 10.1109/ICIP.2011.6116068 Published: 2011Abstract:Accurate image segmentation is important for many medical imaging applications, whereas it remains challenging due to the complexity in medical images, such as the complex shapes and varied neighbor structures. This paper proposes a new hierarchical 3D image segmentation method based on patient-specific shape prior and surface patch shape statistics (SURPASS) model. In the segmentation process, a coarse-to-fine, two-stage strategy is designed, which contains global segmentation and local segmentation. In the global segmentation stage, patient-specific shape prior is estimated by using manifold learning techniques to achieve the overall segmentation. In the second stage, SURPASS is computed to solve the problem of poor segmentation at certain surface patches. The effectiveness of the proposed 3D image segmentation method has been demonstrated by the experiments on segmenting the prostate from a series of MR images. ? 2011 IEEE.Accession Number: 20120514730127 -
Record 128 of
Title:Probability of acquisition of three-dimensional imaging laser radar
Author(s):Dong, Li-Jun(1,2); Zhu, Shao-Lan(1); Sun, Chuan-Dong(1); Gao, Cun-Xiao(1); Song, Zhi-Yuan(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8192 Issue: DOI: 10.1117/12.901932 Published: 2011Abstract:Three-dimensional imaging laser radar (3-D ladar) is widely used in area of modern military, scientific research, agriculture and industry. Because of its many features such as angle-angle-range capturing, high resolution, anti-jamming ability and no multipath effect ,but it has to scan for target searching, acquiring and tracking. This paper presents a novel probability model of target acquiring which provides a theoretical basis for optimizing the scanning mechanism. The model combines space and time, target moving velocity and ladar scanning velocity together. Then the optimum scanning mechanism to obtain the maximum probability of acquisition and associated with different targets can be gained. The result shows that this model provides a method to optimize parameter for designing of the scanner. ? 2011 SPIE.Accession Number: 20113714320170 -
Record 129 of
Title:Spatial domain display for interference image dataset
Author(s):Wang, Cai-Ling(1); Li, Yu-Shan(2); Liu, Xue-Bin(1); Hu, Bing-Liang(1); Jing, Juan-Juan(1); Wen, Jia(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 31 Issue: 11 DOI: 10.3964/j.issn.1000-0593(2011)11-3158-05 Published: November 2011Abstract:The requirements of imaging interferometer visualization is imminent for the user of image interpretation and information extraction. However, the conventional researches on visualization only focus on the spectral image dataset in spectral domain. Hence, the quick show of interference spectral image dataset display is one of the nodes in interference image processing. The conventional visualization of interference dataset chooses classical spectral image dataset display method after Fourier transformation. In the present paper, the problem of quick view of interferometer imager in image domain is addressed and the algorithm is proposed which simplifies the matter. The Fourier transformation is an obstacle since its computation time is very large and the complexion would be even deteriorated with the size of dataset increasing. The algorithm proposed, named interference weighted envelopes, makes the dataset divorced from transformation. The authors choose three interference weighted envelopes respectively based on the Fourier transformation, features of interference data and human visual system. After comparing the proposed with the conventional methods, the results show the huge difference in display time.Accession Number: 20114614524960 -
Record 130 of
Title:A new model and improvement on test methods of the readout noise in the CCD camera
Author(s):Yang, Zuoting(1,2); Ruan, Ping(1); Ge, Wei(1); Wang, Hong(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8321 Issue: DOI: 10.1117/12.905128 Published: 2011Abstract:In this paper, a comprehensive model is developed for the scientific CCD camera readout noise. The readout noise can significantly reduce the ability of weak signal detection and ultimately affects the performance of an image processing approach to some extent. The different readout noise sources in scientific CCD camera are well documented, however, there has been little paper on the development of an all-sided readout noise model about the scientific CCD camera. Based on the proposed model, this paper presents a new test method that is present for choosing the standard section by defining criteria of optimality. The proposed method can get the more accurate readout noise than the test method used by experiment and analysis. Besides, the proposed method is fast and simple and therefore can be fitted in the analysis of data and post-image processing, which have very important application in analysis of the CCD camera other performance indicators. ? 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Accession Number: 20120114664522 -
Record 131 of
Title:An algorithm of decomposing disorder encoding spectrum of HTSI using laser
Author(s):Liu, Caifang(1,2); Hu, Bingliang(1); Yan, Peng(1); Qian, Qingming(1,2); Liu, Lei(1,2)Source: Proceedings 2011 International Conference on Transportation, Mechanical, and Electrical Engineering, TMEE 2011 Volume: Issue: DOI: 10.1109/TMEE.2011.6199558 Published: 2011Abstract:In order to improve the accuracy of recovered spectrum of Hadamard Transform Spectral Imager (HTSI), an algorithm of decomposing disorder encoding spectrum of HTSI using laser is proposed. The theory of Hadamard Transform (HT) is introduced. HTSI, which was developed in the Key Laboratory of Spectral Imaging Technique of Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Science in the world first, is presented. The reason why there existing the phenomenon that some spectra encoded disorderly is analyzed deeply. Experiments have been done in the laboratory according to the algorithm using laser with a wavelength of 632.8 nm. It is proved that the variance of the recovered spectrum can be decreased to approximately 3% compared with traditional spectrum recovering method. It has made great contribution to spectrum recovering in laboratory and projects. ? 2011 IEEE.Accession Number: 20122315082953 -
Record 132 of
Title:A comparative study on model-based pose estimation of flying objects with different feature descriptors
Author(s):Tang, Hui-Jun(1,2); Wen, Jia(1,3); Ma, Cai-Wen(1); Zhou, Ren-Kui(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8196 Issue: DOI: 10.1117/12.900949 Published: 2011Abstract:Methods for pose estimation of flying objects are introduced. Among them is the model-based optical method. We focus on the feature description aspect in model-based method. Feature descriptors of chain codes, moments, Fourier descriptors are used for 2D silhouette or region description. Common issues and techniques, particularly representation and normalization, of such three kinds of descriptors in the application of model-based pose estimation are analyzed. We build a Matlab pose estimation framework to compare pose estimation procedures using different feature descriptors. A missile model of MilkShape 3D file format is created as the simulation object. Experiments concerning with the abilities of descriptors are proceeded to show the difference of these descriptors. ? 2011 SPIE.Accession Number: 20113614296289