2012
2012
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Record 1 of
Title:Image quality assessment-a multiscale geometric analysis-based framework and examples
Author(s):Gao, Xinbo(1); Lu, Wen(1); Tao, Dacheng(2); Li, Xuelong(3)Source: Handbook of Natural Computing Volume: 1-4 Issue: DOI: 10.1007/978-3-540-92910-9_11 Published: January 1, 2012Abstract:This chapter is about objective image quality assessment (IQA), which has been recognized as an effective and efficient way to predict the visual quality of distorted images. Basically, IQA has three different dependent degrees on original images, namely, full-reference (FR), noreference (NR), and reduced-reference (RR). To begin with, we introduce the fundamentals of IQA and give a broad treatment of the state-of-the-art. We focus on a novel framework for IQA to mimic the human visual system (HVS) by incorporating the merits from multiscale geometric analysis (MGA), contrast sensitivity function (CSF), andWeber's law of just noticeable difference (JND). Thorough empirical studies were carried out using the laboratory for image and video engineering (LIVE) database against subjective mean opinion score (MOS), and these demonstrate that the proposed framework has good consistency with subjective perception values and the objective assessment results well reflect the visual quality of the images. ? Springer-Verlag Berlin Heidelberg 2012. All rights are reserved.Accession Number: 20182705501402 -
Record 2 of
Title:Picosecond laser-induced formation of spikes in a single crystal superalloy
Author(s):Zhang, Wei(1,2); Cheng, Guanghua(2); Feng, Qiang(1,3); Cao, Lamei(4)Source: Applied Surface Science Volume: 258 Issue: 23 DOI: 10.1016/j.apsusc.2012.02.056 Published: September 15, 2012Abstract:The characteristics of laser-induced periodic surface structures (LIPSS) were investigated after laser irradiation with different pulse duration under a certain range of laser fluence (0.25 ≤ Φ ≤ 1.91 J/cm2) and pulse number (11 ≤ N ≤ 560). Spikes were generated by picosecond laser irradiation in ambient air, in comparison with only periodic ripple structures introduced by nanosecond and femtosecond laser irradiation. Microstructural investigations indicate that these spikes were initiated by the fragment of periodic ripple ridges or corrugation on the smooth surface with subsequent pulses, and their separation increased with increasing the laser fluence. Surface capillary waves associated with the resolidification process can be employed to explain the formation of spikes by picosecond laser irradiation. ? 2012 Elsevier B.V.Accession Number: 20123215307718 -
Record 3 of
Title:Development of a stable dielectric-barrier discharge enhanced laminar plasma jet generated at atmospheric pressure
Author(s):Tang, Jie(1); Li, Shibo(1); Zhao, Wei(1); Wang, Yishan(1); Duan, Yixiang(1,2)Source: Applied Physics Letters Volume: 100 Issue: 25 DOI: 10.1063/1.4729818 Published: June 18, 2012Abstract:A stable nonthermal laminar atmospheric-pressure plasma source equipped with dielectric-barrier discharge was developed to realize more efficient plasma generation, with the total energy consumption reduced to nearly 25% of the original. Temperature and emission spectra monitoring indicates that this plasma is uniform in the lateral direction of the jet core region. It is also found that this plasma contains not only abundant excited argon atoms but also sufficient excited N2 and OH. This is mainly resulted from the escape of abundant electrons from the exit, due to the sharp decrease of sustaining voltage and the coupling between ions and electrons. ? 2012 American Institute of Physics.Accession Number: 20122715218736 -
Record 4 of
Title:Spectrum recovery revision algorithm of Hadamard transform spectrometer
Author(s):Liu, Lei(1,2); Hu, Bingliang(1); Kong, Liang(1,2); Liu, Qiang(1); Yan, Peng(1); Yu, Tao(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 41 Issue: 7 DOI: Published: July 2012Abstract:An algorithm was proposed to improve the spectrum recovery of the Hadamard transform spectrometer that based on digital micro-mirror device (DMD). Spectral data obtained by the imaging sensor were first analyzed, and then considering the geometric dimension of the micro-mirror slit and the pixels, a spectral correction algorithm for recovery was proposed. Simulation results show that the algorithm can effectively improve the quality of the images, and there is over a 98.88% similarity between the spectrum of the revised dark fringe pixels and that of its adjacent normal pixels before correction.Accession Number: 20123915473073 -
Record 5 of
Title:A novel weighted edge-directed and weighted-color-difference interpolation for demosaicking bayer-pattern color images
Author(s):Bu, Fan(1,3); Qiao, Weidong(2); Qiu, Yuehong(1); Yang, Jianfeng(2); Yan, Xingtao(2,3)Source: Journal of Information and Computational Science Volume: 9 Issue: 7 DOI: Published: July 2012Abstract:Demosaicking is a process of obtaining a full-color image by interpolating missing color components of an image from CFA. This paper introduces a new interpolation algorithm for demosaicking Bayer-pattern color images. The first step is to estimate interpolation direction taking advantage of all adjacent pixels, and use calculated optimal weighting factors to carry on G channel interpolation. Then according to the weighted color-difference rule, R/B components are interpolated and G components are updated with more known pixels. Lastly, using variance-constrained condition, the iterative interpolation repeats until approaching the optimal results. Based on the experiments of 24 Kodak images, the performance of the proposed one outperforms various traditional algorithms both in numerical and visual aspects. It is shown that the proposed algorithm can lead to an improvement in PSNR of about 20.99%, and in ΔEab* of about 8.53%. Furthermore, this new algorithm has been applied on the images captured from panoramic camera and received excellent results. 1548-7741/Copyright ? 2012 Binary Information Press.Accession Number: 20123115297042 -
Record 6 of
Title:Hybrid refractive/diffractive optical system design for light and compact uncooled longwave infrared imager
Author(s):Wang, Hu(1,2); Bai, Yu(3); Luo, Jianjun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8416 Issue: DOI: 10.1117/12.975749 Published: 2012Abstract:Compares with traditional optics,the difractive optical element(DOE) has unique property of minus dispersion.The special state can be used in the optical system to improve performance,lighten weight and reduce volume effectively.In the paper,an infrared optical system with DOE for LWIR thermal imager is proposed.The primary optical parameters of thermal imager are wavelength range 8.0- 12.0μm,effective focal length (EFL) 150 mm,f/numbe 1.0 and field of view 8.58 degrees.The system uses uncooled infrared detector with 320×240 pixels and 45μm pixel size. The f/number matches the sensitivity range of detector array. The infrared optical system is designed by CODE-V optical design software.It is consisted of two lens,the materials of the two lenses are Germanium.The DOE is fabricated on the convex of the first lens and it can be fabricated by diamond turning technology.The imaging quafity of the optical system approached to diffraction limit.The value of modulation transfer function (MTF) at Nyquist frequency(11lp/mm) is great than 0.78. ? 2012 SPIE.Accession Number: 20131416168552 -
Record 7 of
Title:Improved bidirectional image registration based on Radon-SIFT
Author(s):Bu, Fan(1,3); Qiu, Yuehong(1); Liu, Jinxia(1,3); Yan, Xingtao(2,3)Source: Journal of Computational Information Systems Volume: 8 Issue: 12 DOI: Published: June 15, 2012Abstract:Aiming at the problems of large calculation, high complexity and long time-consuming in Scale Invariant Feature Transform (SIFT) feature matching algorithm, this paper proposes a novel bidirectional Radon-SIFT matching algorithm. Based on Radon transform, we make 36 beelines on different directions in local keypoints region. Along these 36 directions, we calculate Radon transform integral values which can be chosen as keypoints vector descriptors. 36-dimensional Radon-SIFT descriptors outweigh the standard 128-dimensional ones both in accuracy and efficiency. The other contribution of this paper is bidirectional matching algorithm. This improved algorithm introduces matching uniqueness constraint to further reduce matching error. To demonstrate the effectiveness and robustness of the proposed algorithm, we apply it to natural images. Experimental results show greater accuracy and faster matching. ? 2012 Binary Information Press.Accession Number: 20122715215296 -
Record 8 of
Title:Focal length and focal depth of metallic superlens
Author(s):Cao, Pengfei(1,2); Cheng, Lin(1); Li, Ying(1); Zhang, Xiaoping(1); Kong, Weijie(1); Gong, Li(1); Zhao, Xining(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8418 Issue: DOI: 10.1117/12.970609 Published: 2012Abstract:We consider the problems of focal length and focal depth of subwavelength imaging via a silver slab of metallic superlens. The performance limit of the metallic superlens was associated with the losses in the metallic film. The transmittance through a metal film is quite low and decreases exponentially with the thickness of the metal film. In the visible wavelength region, the permittivity of Ag can be approximated by the Drude model, so it can be described as the plural permittivity. The real part (Ε') of permittivity of the metal slab has been preferably index matched to the host material, and the imaginary part (Ε'') is considered to prevent ideal reconstruction of the image. Because superlens are usually made of metals with significant intrinsic loss (Ε''>0), the image is blurred and it is regarded as an ultimate limitation to a near field perfect lens. The real part (Ε')and the imaginary part (Ε'') of permittivity of the metal slab is the function of the incident wavelength, so we discuss the relationship of the focal length, focal depth and the incident wavelength. We also derive the expression for the resolution limit of metallic lens and demonstrate that the area of its subwavelength performance is usually limited to the near-field zone. ? 2012 SPIE.Accession Number: 20131416173442 -
Record 9 of
Title:Characterization of stable brush-shaped large-volume plasma generated at ambient air
Author(s):Tang, Jie(1); Cao, Wenqing(1); Zhao, Wei(1); Wang, Yishan(1); Duan, Yixiang(1,2)Source: Physics of Plasmas Volume: 19 Issue: 1 DOI: 10.1063/1.3672511 Published: January 2012Abstract:A brush-shaped, large-volume plasma was generated at ambient pressure with a dc power supply and flowing argon gas, as well as a narrow outlet slit. Based on the V-I curve and emission profiles obtained in our experiment, the plasma shows some typical glow discharge characteristics. The electron density in the positive column close to the anode is about 1.4 × 1014 cm -3 high, which is desirable for generating abundant amounts of reactive species in the plasma. Emission spectroscopy diagnosis indicates that many reactive species, such as excited argon atoms, excited oxygen atoms, excited nitrogen molecules, OH and C2 radicals, etc., generated within the plasma are distributed symmetrically and uniformly, which is preferable to some chemical reactions in practical applications. Spectral measurement also shows that the concentration of some excited argon atoms increases with the argon flow rate when the applied voltage is unvaried, while that of these excited argon atoms declines with the discharge current in the normal/subnormal glow discharge mode with the argon flow rate fixed. The plasma size is about 15 mm × 1 mm × 19 mm (L, W, H), when 38-W of discharge power is used. Such a laminar brush-shaped large-volume plasma device ensures not only efficient utilization of the plasma gas, but also effective processing of objects with large volume and complicated structure that are susceptible to high temperatures. ? 2012 American Institute of Physics.Accession Number: 20121414922203 -
Record 10 of
Title:Optical transmittance measurement system for coated elements with low transmittance
Author(s):Wang, Hongyun(1,2); Da, Zhengshang(1); Liu, Lili(1); Zhao, Juanning(1,2)Source: Applied Optics Volume: 51 Issue: 13 DOI: 10.1364/AO.51.002395 Published: May 1, 2012Abstract:The low-transmittance elements required for a high power laser facility have stringent specifications about transmittance. To validate optic performance against specifications, a metrology system for transmittance is proposed. The system is composed of a laser source, an integrating sphere, a power meter, and four uncoated wedged glasses. A relative measurement method is adopted, which is that the surface reflectivity of uncoated glass is used as the reference to compare with the sample's transmittance. The systematic feature is that uncoated wedged glasses are applied to split and reflect beams, which not only avoid coating errors, but also make the two beam powers attenuate properly. Measurement results for a sample's transmittance are presented. Experiment and analysis show that the relative standard uncertainty (σT/T) of measurement is 0.424%. This system is available for large-aperture elements. ? 2012 Optical Society of America.Accession Number: 20122115047523 -
Record 11 of
Title:A robust random number generator based on differential comparison of chaotic laser signals
Author(s):Zhang, Jianzhong(1,2); Wang, Yuncai(1,2); Liu, Ming(1); Xue, Lugang(1); Li, Pu(1); Wang, Anbang(1,2); Zhang, Mingjiang(1,2)Source: Optics Express Volume: 20 Issue: 7 DOI: 10.1364/OE.20.007496 Published: March 26, 2012Abstract:We experimentally realize a robust real-time random number generator by differentially comparing the signal from a chaoticsemiconductor laser and its delayed signal through a 1-bit analog-to-digital converter. The probability density distribution of the output chaotic signal based on the differential comparison method possesses an extremely smallcoefficient of Pearson's median skewness (1.5 × 10 -6), which can yield a balanced random sequence much easily than the previously reported method that compares the signal from the chaotic laser with a certain threshold value. Moveover, we experimently demonstrate that our method can stably generate good random numbers at rates of 1.44 Gbit/s with excellent immunity from external perturbations while the previously reported method fails. ? 2012 Optical Society of America.Accession Number: 20121514937037 -
Record 12 of
Title:Improvement of interfacial adhesion strength and thermal stability of Cu/p-SiC:H/SiOC:H film stack by plasma treatment on the surface of Cu film
Author(s):Liu, Bo(1); Yang, Jijun(1); Jiao, Guohua(2); Xu, Kewei(3)Source: Plasma Science and Technology Volume: 14 Issue: 7 DOI: 10.1088/1009-0630/14/7/12 Published: July 2012Abstract:A highly reliable interface of self-aligned barrier CuSiN thin layer between the Cu film and the nano-porous SiC:H (p-SiC:H) capping barrier (k=3.3) has been developed in the present work. With the introduction of self-aligned barrier (SAB) CuSiN between a Cu film and a p-SiC:H capping barrier, the interfacial thermal stability and the adhesion of the Cu/p-SiC:H film are considerably enhanced. A significant improvement of adhesion strength and thermal stability of Cu/p-SiC:H/SiOC:H film stack has been achieved by optimizing the pre-clean step before cap-layer deposition and by forming the CuSiN-like phase. This cap layer on the surface of the Cu can provide a more cohesive interface and effectively suppress Cu atom migration as well.Accession Number: 20123215311470