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Record 73 of
Title:Color to gray: Visual cue preservation
Author(s):Song, Mingli(1); Tao, Dacheng(2); Chen, Chun(1); Li, Xuelong(3); Chen, Chang Wen(4)
Source: IEEE Transactions on Pattern Analysis and Machine Intelligence Volume: 32 Issue: 9 DOI: 10.1109/TPAMI.2009.74 Published: 2010
Abstract:Both commercial and scientific applications often need to transform color images into gray-scale images, e.g., to reduce the publication cost in printing color images or to help color blind people see visual cues of color images. However, conventional color to gray algorithms are not ready for practical applications because they encounter the following problems: 1) Visual cues are not well defined so it is unclear how to preserve important cues in the transformed gray-scale images; 2) some algorithms have extremely high time cost for computation; and 3) some require human-computer interactions to have a reasonable transformation. To solve or at least reduce these problems, we propose a new algorithm based on a probabilistic graphical model with the assumption that the image is defined over a Markov random field. Thus, color to gray procedure can be regarded as a labeling process to preserve the newly well-defined visual cues of a color image in the transformed gray-scale image. Visual cues are measurements that can be extracted from a color image by a perceiver. They indicate the state of some properties of the image that the perceiver is interested in perceiving. Different people may perceive different cues from the same color image and three cues are defined in this paper, namely, color spatial consistency, image structure information, and color channel perception priority. We cast color to gray as a visual cue preservation procedure based on a probabilistic graphical model and optimize the model based on an integral minimization problem. We apply the new algorithm to both natural color images and artificial pictures, and demonstrate that the proposed approach outperforms representative conventional algorithms in terms of effectiveness and efficiency. In addition, it requires no human-computer interactions. ? 2010 IEEE.
Accession Number: 20103213143004
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Record 74 of
Title:Optimized logarithmic phase masks used to generate defocus invariant modulation transfer function for wavefront coding system
Author(s):Zhao, Hui(1); Li, Yingcai(1)
Source: Optics Letters Volume: 35 Issue: 15 DOI: 10.1364/OL.35.002630 Published: August 1, 2010
Abstract:In a previous Letter [Opt. Lett. 33, 1171 (2008)], we proposed an improved logarithmic phase mask by making modifications to the original one designed by Sherif. However, further studies in another paper [Appl. Opt. 49, 229 (2010)] show that even when the Sherif mask and the improved one are optimized, their corresponding defocused modulation transfer functions (MTFs) are still not stable with respect to focus errors. So, by further modifying their phase profiles, we design another two logarithmic phase masks that exhibit more stable defocused MTF. However, with the defocus-induced phase effect considered, we find that the performance of the two masks proposed in this Letter is better than the Sherif mask, but worse than our previously proposed phase mask, according to the Hubert space angle. ? 2010 Optical Society of America.
Accession Number: 20103213126328
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Record 75 of
Title:Multifocus noisy image fusion algorithm using the contourlet transform
Author(s):Cao, Jian-Zhong(1); Zhou, Zuo-Feng(1); Wang, Hao(1); Liu, Wei-Hua(2)
Source: 2010 International Conference on Multimedia Technology, ICMT 2010 Volume: Issue: DOI: 10.1109/ICMULT.2010.5631461 Published: 2010
Abstract:Multifocus image fusion deals with a stack of images that were acquired with a different focus point to get an image with all the objects in the scene full focused. Considered the noise effect, in this paper, we proposed a multifocus noisy image fusion algorithm using the contourlet transform. Utilizing the captured directional information by the contourlet transform, the directional windows are used to determine the fusion weight. The experiment results demonstrate the higher performance of the proposed multifocus noisy image fusion algorithm compared to the wavelet-based multifocus noisy image fusion method. ?2010 IEEE.
Accession Number: 20111013721889
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Record 76 of
Title:Optimized sinusoidal phase mask to extend the depth of field of an incoherent imaging system
Author(s):Zhao, Hui(1); Li, Yingcai(1)
Source: Optics Letters Volume: 35 Issue: 2 DOI: 10.1364/OL.35.000267 Published: January 15, 2010
Abstract:Wavefront coding is a powerful technique that can be used to extend the depth of field of an incoherent imaging system. By adding a suitable phase mask to the aperture plane, the optical transfer function of a conventional imaging system can be made defocus invariant. Since 1995, when a cubic phase mask was first suggested, many kinds of phase masks have been proposed to achieve the goal of depth extension. In this Letter, a phase mask based on sinusoidal function is designed to enrich the family of phase masks. Numerical evaluation demonstrates that the proposed mask is not only less sensitive to focus errors than cubic, exponential, and modified logarithmic masks are, but it also has a smaller point-spread-function shifting effect. ? 2010 Optical Society of America.
Accession Number: 20100612685755
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Record 77 of
Title:Refinement of microstructure and enhancement of absorption for ultra-strength constructional steel
Author(s):Zhang, Wei-Hu(1,3); Lu, Shu-Yuan(2); Zhang, Fu-Chun(3); Zhang, Zhi-Yong(1)
Source: Cailiao Kexue yu Gongyi/Material Science and Technology Volume: 18 Issue: 3 DOI: Published: June 2010
Abstract:A series of bainitic structural steels with excellent combination of plasticity and toughness was developed by the reasonable design of chemical composition and effective optimization of heat treatment process. On condition that the ultimate tensile strength is over 1470 MPa, the impact energy absorption of V-type notch ( A KV≥132 J) has been doubled compared with that of the previously advanced martensitic steel with same strength level ( σ b>1560 MPa). Based on the results of microstructure analysis, the physical mechanism on the improvement of toughness was deeply discussed.
Accession Number: 20102813067797
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Record 78 of
Title:On the transformation from automata into Petri nets in FMS
Author(s):Zhang, Jian(1); Cao, Jianzhong(1); Wu, Dengshan(1)
Source: 2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010 Volume: Issue: DOI: 10.1109/ICMA.2010.5588899 Published: 2010
Abstract:Automata and Petri nets are both used in research of discrete event systems (DES). Based on supervisory control theory, this paper provides an algorithm to convert automata into Petri nets in flexible manufacturing systems (FMS). The automaton to be transformed should satisfy three conditions: (1) it contains no self-loop, (2) its initial state is also the marker state, and (3) it is nonblocking. The automaton is first divided into several sub-automata by projecting it onto some groups of events. Second the redundant automata are deleted. Then the sub-automata remained are changed separately into places with transitions and arcs in Petri nets formalism. In Petri nets formalism of FMS, places are distinguished by idle, operation, and resource places. We set the initial tokens of idle and resource places to be n - 1 (n is the number of states corresponding to the automaton) and set the initial tokens of the operation places to be zero. Then the places and transitions are connected together to form a complete Petri net. ? 2010 IEEE.
Accession Number: 20104813423741
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Record 79 of
Title:New method to improve measurement accuracy of modulation transfer function
Author(s):Song, Zongxi(1,2); Gao, Wei(1); Zhou, Yan(3); Liu, Feng(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 7656 Issue: PART 1 DOI: 10.1117/12.867707 Published: 2010
Abstract:Modulation transfer function (MTF) of optical systems is often derived by taking Fourier transform (FT) of a measured line spread function (LSF). During MTF measurement process, the measurement accuracy of MTF will decrease as a result when LSF computed is not veracity. Based on the model constructed using the variance information of knife-edge and skew of the knife-edge, this paper presents a new method to improve the accuracy of measurement of MTF. The results showed that the new method can improve the accuracy of MTF to 0.01. ? 2010 Copyright SPIE - The International Society for Optical Engineering.
Accession Number: 20105013487473
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Record 80 of
Title:An optimization detection angle for polarization measurement
Author(s):Jian, Xiaohua(1,2); Zhang, Chunmin(1,2); Zhao, Baochang(3)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 7807 Issue: DOI: 10.1117/12.859422 Published: 2010
Abstract:Based on the basic theory of polarization measurement, this paper compares the differences between two detection angles: 45° and 60°, which are generally used in rotating polarization elements method for polarization measurement. Sequentially, an optimization detection angle is present, and it provides a better angle choice for polarization measurements which could obviously improve the polarization measurement accuracy and effectively reduce the influence of rotation errors to the degree of polarization. ? 2010 Copyright SPIE - The International Society for Optical Engineering.
Accession Number: 20104713417592
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Record 81 of
Title:Real-time compression system research based on DMD hadamard transform spectrometer
Author(s):Fan, Xianyun(1,2); Hu, Bingliang(2); Li, Zitian(2); Chen, Xiaolai(2); Han, Yajuan(1,2)
Source: Procedia Engineering Volume: 7 Issue: DOI: 10.1016/j.proeng.2010.11.048 Published: 2010
Abstract:We propose a new lossy compression approach for hyperspectral images which comes from hadamard transform (HT) spectral imager for space-based surveillance that uses the Digital Micro-mirror Device (DMD) as the programmable mask other than the conventional mechanical mask. This paper firstly introduces that the DMD Hadamard spectrometer described in this paper is good at obtaining multi-channel high-energy high-SNR spectral data, which is superior to traditional ones. And then,based on the hardware platform composed of Xilinx FPGA and ADV212 (a codec chip for special JPEG2000), the sampled image data was then compressed with high SNR,high-resolution compression ratio. Last, we show the experimental results which demonstrate that the PSNR is up to 47.3dB and make no significant distortion for vision. Obviously, this approach takes distinguished advantages on real-time ability, image distortion and the practical value. The design can be utilized in national defense, earth resource survey aerospace, environmental disaster monitoring and other fields. ? 2010 Published by Elsevier Ltd.
Accession Number: 20110813690182
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Record 82 of
Title:Moving corner-cube mirror interferometer and reflection characteristic of corner-cube mirror
Author(s):Yang, Qinghua(1)
Source: Applied Optics Volume: 49 Issue: 21 DOI: 10.1364/AO.49.004088 Published: July 20, 2010
Abstract:A novel moving corner-cube mirror interferometer (MCCMI) is presented. It has neither tilt nor shearing problems. It consists of one moving corner-cube mirror (MCCM), one fixed double-sided mirror (FDSM), one fixed plane mirror, and one beam splitter. The FDSM is a plane-parallel glass plate with both faces coated with high-reflectivity films. The effect of a FDSM tilt is analyzed. The optical path difference (OPD) is created by the straight reciprocating motion of the MCCM, and the OPD value is four times the displacement of the MCCM. The reflection characteristic of the corner-cube mirror (CCM) is analyzed by means of the vector expression, and the formulas of deviation angle of a CCM are derived. The effect of a MCCM deviation angle is analyzed. The new MCCMI is very suitable for high-resolution Fourier-transform infrared spectrometers used for atmospheric sounding. ? 2010 Optical Society of America.
Accession Number: 20103413187327
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Record 83 of
Title:Effect of structural modifications on the switching voltage of a holographic polymer-dispersed liquid crystal lattice
Author(s):Milavec, J.(1); Devetak, M.(1); Li, J.(2); Rupp, R.A.(2,3); Yao, B.(4); Drevenek-Olenik, I.(1,5)
Source: Journal of Optics Volume: 12 Issue: 1 DOI: 10.1088/2040-8978/12/1/015106 Published: 2010
Abstract:The effect of temperature-induced variations of the nematic director field on the switching voltage of a 2D square holographic polymer-dispersed liquid crystal (HPDLC) lattice was investigated for a mixture prepared from UV-curable commercially available constituents. At temperatures far below the nematic-isotropic phase transition, the switching voltage is governed by the domain structure of the director field, while at temperatures close to the phase transition it is governed by elastic and dielectric properties of the liquid crystal (LC) material. The crossover occurs at the temperature at which a thin interface region between the LC domains and the polymer pilasters is melted into the isotropic phase. We also performed a comparative study of the square lattices recorded with the use of four and three coherent beams and resolved numerous differences in their structural and switching properties that arise from different spatial profiles of the associated interference fields. ? 2010 IOP Publishing Ltd.
Accession Number: 20101912913824
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Record 84 of
Title:Azimuthons in weakly nonlinear waveguides
Author(s):Zhang, Yiqi(1,2); Skupin, Stefan(1,3); Lu, Keqing(2); Królikowski, Wieslaw(4)
Source: Optics InfoBase Conference Papers Volume: Issue: DOI: 10.1364/np.2010.nme9 Published: 2010
Abstract:We show that a weakly guiding nonlinear waveguide supports propagation of stable rotating solitons, azimuthons. We calculate analytically the rotation frequency of these solitons and find it to be in agreement with numerical simulations. ? 2010 Optical Society of America.
Accession Number: 20141117446841
