Acta Photonica Sinica
Co-Editors-in-Chief
Yue Hao
ZHAO Bao-chang, YANG Jian-feng, XUE Bin, QIAO Wei-dong, and QIU Yue-hong

The Sagnac Spatially-Modulation Interference Imaging Spectrometer was one of the Chang’E-1 Satellite payload,The Calibration methods of it was first introduced,including Row-Flat-fields principle,and Spectrum-Contrast-Method among varied types of spectrometers,which were applied to the relative and absolute radiometric calibration of instrument.Others,the spectral position and spectral resolution were measured,and radiometric uncertainty of instrument on orbit was evaluated.The above-mentioned principles and results were first advanced both at home and aboard.The scheme of interference imaging spectrometer first successfully obtain the visible-near infrared broad spectral range and continual spectrum of the moon.

Aug. 24, 2021
  • Vol. 39 Issue 5 769 (2010)
  • LIU Quan-xi, and ZHONG Ming

    A numerical model of the rod laser medium end-pumped by laser-diode array (LDA) is set up.Under considering the influence of temperature correlation of the thermodynamic parameters of the material and heat transfer coefficient between air and medium,based on the thermal conduction equations and the thermal-elastic equations,the transient distributions of temperature and thermal stress and strain in the rod medium are calculated by a finite element analysis method.The influence disciplinarian of the pump power on thermal lens focal length in the medium is analyzed.The theoretical results accord with interrelated experiment and provide theoretical reference for the design of solid laser pumped by LDA and experimental study.

    Aug. 24, 2021
  • Vol. 39 Issue 5 776 (2010)
  • LIU Yuan-zheng, WANG Jing-xian, MA Yang-hua, and LAN Pei-feng

    The output characteristic of the traveling waves in the cavity is analyzed and it is found that the conventional lock-in control techniques have some disadvantages.The lock-in error discriminant signal is deduced from the equations for laser gyro.The high signal-to-noise ratio controlling means are implemented by the operation of beat frequency signal and cavity length signal.It is concluded that the approach is applicable to both constant biased and alternating biased laser gyro,and the the lock-in zone of laser gyro is precisely controlled in the operating temperature range.

    Aug. 24, 2021
  • Vol. 39 Issue 5 781 (2010)
  • WU Zhi-chao, LING Ming, WANG Fu-rong, and LIANG Zhu

    The high repetition electro-optical Q-switched red laser is studied based on the polarized characteristic of Nd∶YAP crystal.The parameters of the three-mirror folded are optimized by the thermal focus length of Nd∶YAP crystal.The electro-optical Q-switched of LN crystal and typeⅡnoncritical phase-matching intracavity frequency-doubling of KTP crystal are adapted.Then the output peak power with 28.3 kW,about 76 ns of pulse duration at 670 nm and the frequency doubling efficiency of 37.1% are obtained in the condition of 75 A pump current and the electro-optical Q-switched repetition rate of 1 kHz.

    Aug. 24, 2021
  • Vol. 39 Issue 5 785 (2010)
  • REN Guang-jun, and YAO Jian-quan

    The theory of voltage-tunable liquid crystal filter is elaborated,and the change of transmission of BL-009 nematic liquid crystal in visible light band is detailedly analyzed by testing the transmission of liquid crystal using Shimadzu UV-23101 spectrophotometer.Relation curve of transmission with voltage is gained in the wavelength range from 400 nm to 800 nm.The spectral lines at 488 nm wavelength and at 514.5 nm wavelength of argon ion laser are separated.

    Aug. 24, 2021
  • Vol. 39 Issue 5 789 (2010)
  • ZHENG Yu, WANG Jing-quan, LI Ming, NIU Xiao-yun, and DU Jing-lei

    Based on the models of thin-layer resist exposure and developing,the SPPs resist exposure model is established.Two kinds of resist of AZ1500 and AR3170 are chosen to simulate the process of exposure and developing,and the final profile of SPPs lithography is obtained.Some craft optimization conditions are also conclucled.The research results are for experiment and future work of SPPs lithography.

    Aug. 24, 2021
  • Vol. 39 Issue 5 792 (2010)
  • CHEN Tao, LIANG Zhong-cheng, XU Ning, Qian Chen, ZHAO Rui, and BI Lan

    A novel space optical switch device of optofluidic is proposed to solve the problems of electrical controlling without mechanical device.The basic structure of the switch includes a core exchange space sandwiched between two optical arrays.The basic unit of array is made from liquid prism as a beam control unit including three kinds of immiscible liquids(water / oil / water).Through the electro-wetting effect,the beam deflection angle of the liquid prism can be adjusted about -15 °~15 °continuously in a specific voltage range(30 ~ 110 V).Thus one can construct a variety of two-dimensional or even three-dimensional optical switch array.

    Aug. 24, 2021
  • Vol. 39 Issue 5 797 (2010)
  • HUANG Chang-qing, TIAN Wei-jian, FENG Gui-lan, and CHEN Hui-fang

    Eu(TTFA)3-doped SiO2 hybrid spheres are synthesized by the modified St?ber method and seed growth method,and characterized by the transmission electron microscope and fluorescence spectrometer.The results show that SiO2 hybrid spheres doped wih Eu(TTFA)3 synthesized by both the two methods have smooth surface and good monodispersity and exhibit the characteristic photoluminescence of the Eu3+ ions.After Eu(TTFA)3 doped into SiO2 spheres,the absorption intensities of the ligand TTFA obviously increase in the short wavelength range and its maxium accordingly shifts about 20 or 30 nm to shorter wavelength.Under the influence of SiO2 matrix,5D0→7F2 transition of Eu3+ ions doped into SiO2 spheres still appears to be narrow and its fluorescent peaks slightly change.

    Aug. 24, 2021
  • Vol. 39 Issue 5 802 (2010)
  • WU Lin, ZHANG Fan, LI Li, CHEN Zhang-yuan, and XU An-shi

    The all-optical amplitude regeneration of both nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero DPSK (RZ-DPSK) signals at a bit rate of 42.8 Gbit/s is demonstrated experimentally, utilizing saturation of four-wave mixing in a highly nonlinear optical fiber (HNLF). The power transfer curves of the HNLF for both NRZ-DPSK and RZ-DPSK signals are measured. The regenerative performance for both modulation formats are compared at the same average input power of 16 dBm. Experiment results show that the RZ-DPSK signal exhibits better performance of amplitude regeneration.

    Aug. 24, 2021
  • Vol. 39 Issue 5 807 (2010)
  • LIANG Rui, ZHOU Xiao-jun, ZHANG Zhi-yao, QIN Zu-jun, LI He-ping, and LIU Yong

    The spectral compression performance of the fundamental soliton in a dispersion-increasing fiber is investigated through numerically solving the generalized nonlinear Schrdinger equation.The influence of the input peak power on the output spectral width and the output center wavelength is analyzed,and the evolution of the pulse width,the spectral width and the chirping in the fiber are described.The calculation results show that spectral compression from 12.6 nm to 5.2 nm,i.e.spectral compression rate of 2.42,can be realized for the fundamental soliton with the pulse width of 200 fs and the center wavelength of 1 550 nm propagating in the dispersion-increasing fiber with the length of 100 m whose group-velocity dispersion parameter linearly varies from -1 ps2/km to -11 ps2/km.

    Aug. 24, 2021
  • Vol. 39 Issue 5 811 (2010)
  • ZHANG Zu-xing, DAI Guo-xing, KUANG Qing-qiang, SANG Ming-huang, and YE Zhi-qing

    A spacing-adjustable multiwavelength fiber laser based on self-excited stimulated Brillouin scattering without external Brillouin pump is proposed.The nonlinear gain of self-excited stimulated Brillouin scattering can suppress mode competition induced by homogeneous broadening of erbium-doped fiber.With the use of a birefringence fiber loop filter,the wavelength spacing can be adjusted by changing the length of the used birefringence fiber,which makes the laser more flexible.Multiwavelength output with adjustable spectral spacing from 0.8 nm to 0.076 nm is experimentally obtained.And the wavelength number increases as the decrease of wavelength spacing.

    Aug. 24, 2021
  • Vol. 39 Issue 5 815 (2010)
  • FENG Gao-feng, WU Jun, PAN Jin, and ZHANG Li-yong

    Yb3+ doped silica glass preforms are fabricated by MCVD process combined with the solution doping technique.Absorption and emission spectra of preforms with various Yb3+ concentrations are investigated.The intensities of absorption and emission increase with increasing of solution concentrations of YbCl3.The maximum YbCl3 solution concentration can be doped into core layer of preform without compromising vitrification is 0.057 mol/L.

    Aug. 24, 2021
  • Vol. 39 Issue 5 820 (2010)
  • CAI Zhi-bin, ZHOU Mao, and GAO Jian-rong

    Six new anthracenedione compounds are synthesized and characterized by UV-vis,IR,1H NMR and elemental analysis.By using femtosecond laser,the off-resonant third-order optical nonlinearities of the compounds are measured with degenerate four-wave mixing technique.The third-order nonlinear optical susceptibilities χ(3) are 2.62~3.55×10-13.The nonlinear refractive indexes n2 are 4.82~6.52×10-12 esu.The second-order hyperpolarizabilities γ of the molecules are 2.57~3.25×10-31 esu.The response times τ are 91~116 fs.The influence of the molecular structure on the third-order optical nonlinearity is studied.The factors such as long conjugate chain,formation of donor-acceptor-donor srtucture,strong electron-donating abilities of substituents,and good coplanarity lead to the high third-order optical nonlinearity.

    Aug. 24, 2021
  • Vol. 39 Issue 5 823 (2010)
  • CAI Tuo, SANG Tian, and ZHANG Xiao-wei

    By properly choosing the parameters of the non-linear Schrdinger equation which satisfies the optical soliton propagation,and by using independent analysis and the comprehensive analysis for the factors such as dispersion and non-linearity which influences Gauss pulses propagation,two conclusions are obtained.The second-order dispersion mainly influences the pulse amplitude but the pulse shape,and the chirp effect is the key factor for the pulse distortion.The chirp,the third-order dispersion and the fifth-order nonlinearity simultaneously influence the pulse propagation,and they also influence and interact with each other.As they approach a certain parameter,the high gain effect and the reshape effect occur in the propagation of the pulse.The improvement method for the characteristics of pulse propagation is theoretically proposed based on the analysis and simulation results,which has theoretical importance for the practice of soliton optical fiber communication.

    Aug. 24, 2021
  • Vol. 39 Issue 5 829 (2010)
  • DONG Li-juan, JIANG Hai-tao, LI Yun-hui, DU Gui-qiang, SHI Yun-long, and YANG Cheng-quan

    The transmission properties of defect modes for a doped one-dimensional photonic crystal (1DPC) surrounded by an μ-negative layer and a μ-negative layer are studied. The reflection phase spectra of μ-negative and a μ-negative media and the transmission phase spectra of the doped 1DPC are calculated by means of the transfer matrix method. It is found that the sum of the reflection phases of μ-negative and a μ-negative layers and the double transmission phases of the doped 1DPC under special conditions are zero or integer multiple of 2π.The results show that only one defect mode appears in the photonic gap when the doped 1DPC surrounded by an μ--negative layer and a μ-negative layer, regardless of the thickness of the defect. Moreover, the quality factor of the single defect mode is enhanced greatly due to the confinement effect of the ε-and μ-negative layers.

    Aug. 24, 2021
  • Vol. 39 Issue 5 834 (2010)
  • WANG Jing-wei, HAN Pei-de, XIA Ling-qin, and ZHANG Rui-zhen

    In order to obtain an excellent photonic band gaps of visible and near infrared region,the formation of band gaps of MgF2、Ta2O5 and Ta2O5/MgF2 heterostructure three-dimensional photonic crystal is exhibited and confirmed by calculation of the transfer matrix method.It is shown that the three-dimensional photonic crystal with the heterostructure of Ta2O5/MgF2 has omnidirectional band gaps without influence of incident angles around 820~1 020 nm of near infrared region with TM polarization.The structure should enable new applications for polarizing devices.

    Aug. 24, 2021
  • Vol. 39 Issue 5 839 (2010)
  • SU An, and GAO Ying-jun

    The transfer matrix method is used to research the transmission spectra for one-dimensional photonic crystal of the solid dielectric constant and when containing the complex dielectric constant.The results show that the photonic quantum-well structure can be made up in both circumstances,and the position and struct of the transmission band spectra of the photonic quantum-well structure are the same.But the resonance transmission peak arises strong gain phenomenon in the circumstance that contains the negative imaginary part of the complex dielectric constant,and evident attenuating phenomenon in the circumstance that contains the positive imaginary part of the complex dielectric constant.

    Aug. 24, 2021
  • Vol. 39 Issue 5 842 (2010)
  • LIU Qi-neng

    Transmission characteristics of electromagnetic wave in 1D rectangle photonic crystal are obtained with restrictions condition of electromagnetic wave and the characteristics of mode are studied.Transmission characteristics of electromagnetic wave are calculated by the dispersion method.The new characteristics of electromagnetic wave in 1D rectangle photonic crystal are obtained.The bandgap of 1D rectangle photonic crystal is determined by quantum number of mode.The center and width of the bandgap are determined by the quantum number of mode and the side length of rectangle.

    Aug. 24, 2021
  • Vol. 39 Issue 5 847 (2010)
  • LI Hong-guang, ZHANG Peng-shun, and DA Zheng-shang

    According to requirements of the system and special imaging characters of ellipsoidal surface,a design methode-using off-ellipsoidal surface to achieve beam sampling and perfect imaging is presented.With design input,the initial configuration parameter is calculated,and the conic function of off-ellipsoidal surface is obtained.Calculation results are substituted to optical design software ZEMAX to verify imaging quality.The result shows that the off-ellipsoidal surface splits the objective point and the imaging point,reduces the length of the system,gets a perfect imaging on the imaging point,and transfers the off-axis imaging to a axis imaging,which can achieve the high quality imaging of the back focal spot system easily.

    Aug. 24, 2021
  • Vol. 39 Issue 5 851 (2010)
  • WANG Yao, WANG Zhao-qi, and ZHANG Mei

    A portable fundus fluorescein angiography(FFA)camera is designed based on Gullstrand-Le Grand eye model.Nikon filter combination of B-2A is used as filter system in this design.And after the comprehensive consideration of both the optical system of human eye and the camera,a high definition image with 2 mega pixels in its full field of view is realized.Meanwhile,the coaxial illumination system is designed with an annular stop,in order that the eyeground is uniformly illuminated.It is shown that this camera has strong abilities for accommodation,which could adapt the different eyes from -10D to +8D.The field of view of this camera is 30°,the resolution of the image surface is 120 lp/mm,and the value of the negative distortion is less than 5.3%.

    Aug. 24, 2021
  • Vol. 39 Issue 5 855 (2010)
  • SUN Li-wei, JIN Shang-zhong, and CEN Song-yuan

    To solve the archetypal problem of LED illumination:redistribute the irradiance of a given LED source or any quasi-point sources onto a desired target surface to achieve any prescribed illumination distribution,the free-form micro-lens optics is designed based on the Snell′s law and "edge-ray principle".This secondary optics can redistribute any LED radiations onto the target surfaces to achieve prescribed uniform illuminations without concerning the initial radiation patterns of LED sources.According the practical illumination requirements,the surface shape of the single free-form micro-lens can be calculated by using the ray tracing method and B-spline fitting way.Some modules of free-from micro-lens optics were constructed to achieve rectangular illumination.The simulation results show that the achieved illuminations have high uniformities and precise illuminating shapes as prescribed.The free-form micro-lens optics is applicable in LED lighting,with cogent competitive advantages.

    Aug. 24, 2021
  • Vol. 39 Issue 5 860 (2010)
  • LIU Feng, XU Xi-ping, DUAN Jie, SUN Xiang-yang, and REN Yu-fen

    8~12 μm infrared (IR) hybrid refractive continuous zoom lenses are designed, based on long-wave 160×120 element uncooled thermal IR focal plane arrays (FPA) detector. The continuous zoom system has a large relative aperture, the F#=1.1, high zoom ratio, smooth curve of zoom. Two common infrared materials of Ge and ZnS are used in this optical system. To correct off axis aberration, aspheric surface is accepted, zoom ratio can be improved by solving compensated curves at the middle equivalent focal length,and the optimum design of cam curve has brought the optical axis drift under control in the process of zoom. The modulation transfer function (MTF) is above 0.55 in all focal lengths at the spatial frequency of 17 lp/mm and approaches the diffraction limit.The energy permeance ratio is greater than 78% within the detector sensor limits smaller than17.5μm, which shows that the optical system has good imaging quality.

    Aug. 24, 2021
  • Vol. 39 Issue 5 866 (2010)
  • WANG Fu-guo, LI Hong-zhuang, and YANG Fei

    The thin mirror active optics simulation model is built based on a great deal of domestic and international reference,and the model is analyzed.The simulation result indicates that the active optics can correct low-frequency error.And a thin mirror active optics experiment system is set up,thin mirror active optics experiment is carried on,and the result indicates that the surface figure can be corrected to the coated surface figure(λ/10) through the active optics.And the thin mirror active optics is able to correct Pri Astig best,Pri Spherical and Pri Trefoil better,but Pri Coma hardly,which has some instructions for coating large aperture thin mirrors.

    Aug. 24, 2021
  • Vol. 39 Issue 5 871 (2010)
  • YU Kun, ZHANG Chang-rui, CAO Ying-bin, and LIU Rong-jun

    Design of lightweight hole of honeycombed elliptical mirror is investigated by means of finite element method.Divisional errors of different divisional element sizes are studied,and the effects of hole array and hole diameter on different performance of honeycombed elliptical mirror is analyzed.The results show that smaller divisional error is acquired with divisional element size of 6 mm;weight, inert moment and pressure displacement are significantly influenced by hole diameter; hole array and hole diameter have great effect on thermal displacement than gravity displacement; the third hexagonal hole array with hole diameter of 80 mm is selected out as optimum hole design.

    Aug. 24, 2021
  • Vol. 39 Issue 5 876 (2010)
  • XU Yuan-qiang, WANG Yu-rong, and DING Hai-sheng

    A new autofocusing method for particles located in different plane in particle field detection with digital in-line holography is proposed and experimentally verified by analyzing the characters of recording and reconstructing about digital in line holography.The focus measure function and the operation procedure of particle segmentation identification and independent focusing are presented.The proposed method is verified through the experiments of one layer of one particle,two layers of two particles and multi-layers of multi-particles.

    Aug. 24, 2021
  • Vol. 39 Issue 5 881 (2010)
  • HU Cui-ying, GAO Ying-jun, and ZHONG Jin-gang

    Based on the off-axis lensless Fourier transform digital holography principle,two main determining factors,which effect the imaging resolution of the Fourier transform digital holography are discussed in this paper.One is the recording distance and the size of the object.The other is the size of reference light source.The 1.0×1.0 mm2 and 1.5×1.5 mm2 areas in the center of an USAF 1951 Style Resolution Target serve as the objects.Corresponding experiments are performed employing three reference light sources with the sizes 2 μm,6.5 μm and 15 μm respectively,at different recording distances.Both the theory and the experimental results show that as in meeting three terms (twin images and zero order in reconstructed image) separation from each other and sampling theorem conditions,shortening the recording distance or decreasing scale of the reference light source may improve the system resolution of lensless Fourier transform digital holography of micro object.

    Aug. 24, 2021
  • Vol. 39 Issue 5 888 (2010)
  • YUAN Cao-jin, and ZHAI Hong-chen

    In order to simplify the super-resolution imaging system,a phase mask is proposed and introduced into the object and reference beams part of the digital holographic recording system,respectively,to produce the on-axis and off-axis illumination beams and the sub-reference beams with different carrier frequency.The diffraction fields containing the low and high frequency information can be recorded by the CCD sensor whose position is fixed during the recording process with different illumination beams produced by phase mask.The low and high frequency information can be separated by reference beams with different carrier frequency in the spectrum plane of the composite hologram.After the frequency filtering followed by an inverse Fourier transform,the low and high frequency information can be obtained,and the object wavefront containing the low and high frequency information at the object plane can be obtained by calculating the Fresnel diffraction and removing the additional phases introduced by the object illuminations.The reconstructed image can be obtained by synthesizing the wavefront containing low and high frequency information of the recorded object.It can be known form the experiment that the resolution of the synthesized image is over that determined by the numerical aperture of the recording system.

    Aug. 24, 2021
  • Vol. 39 Issue 5 893 (2010)
  • GUI Jin-bin, LI Jun-chang, LOU Yu-li, PENG Zu-jie, and FAN Ze-bin

    Regarding the test object surface as scattering plane,and using spherical wave as reference wave,with different wavelength illumination,reconstruction position of object plane wave field is studied by using Angular spectrum theory.The result shows that,when the physical meaning of the image is not considered,diffraction image center reconstruction with S-FFT(Single Fourier Transform) is corresponding to the frequency spectrum center of object wave field.Taking the S-FFT reconstruction image as a reference,the location of the object wave field spectrum can be well determined,then the reconstruction field of different wavelength can be accurate overlapped with adjustable magnification reconstruction Angular spectrum method.

    Aug. 24, 2021
  • Vol. 39 Issue 5 897 (2010)
  • GAO Jing, JI Zhong-ying, WANG Zhong-hou, and CUI Yan

    By calculation and experimentation,on-board calibration of SMIFTS is analyzed,and spaceflight environment characteristic of on-board calibration is tested.The key parts difficulty of on-board calibration of SMIFTS:lamp-house,spectrum filter,integrating sphere are solved.The whole-aperture,part-field comparatively wavelength calibration are achieved,and spectrum curve and Before-launch Interferogram is obtained.

    Aug. 24, 2021
  • Vol. 39 Issue 5 902 (2010)
  • CHEN Xiu-li, LIU Jun-xian, SHEN Wei-dong, LI Yong-qing, and WANG Gui-wen

    Raman tweezers is used to probe the oxygen carrying capacity of erythrocytes.The effects of laser power on erythrocytes are compared.An indicator for distinguishing oxygenated and deoxygenated erythrocytes is chosen and utilized to analyze the oxygen carrying capacity of erythrocytes from different storage time and different health state.The result shows that strong power of laser led to the bands at 1 248,1 371 cm-1,the markers of heme aggregation,increasing.The ratio I1 638/I1 547, a well indicator for distinguishing oxygenated state from deoxygenated state,reveals that the oxygen binding capacity of preserved erythrocytes increase as storage time extending,while the deoxidization capacity is not change significantly.Erythrocytes from HbH-CS,an alpha-thalassemia disease,are easier to oxygenate than normal controls,but difficult to deoxygenate.The findings demonstrate Raman tweezers can be a rapid,non-invasive,sensitive technique for analyzing and evaluating the oxygen carrying capacity of erythrocytes.

    Aug. 24, 2021
  • Vol. 39 Issue 5 907 (2010)
  • WANG Zhi-jun, LU Wei, LI Pan-lai, YANG Zhi-ping, GUO Qing-lin, and FU Guang-sheng

    A novel red phosphor, LiSrBO3∶Sm3+, is synthesized by solid state reaction method, and the spectral characteristics are investigated. The emission and excitation spectra indicate that LiSrBO3∶Sm3+ phosphor can be effectively excited by near ultraviolet (UV) (404 nm), and exhibits a satisfactory red performance (599 nm), nicely fitting in with the widely applied UV chips. The effect of Sm3+ concentration on the emission intensity is studied, and the results show that the intensities reach the peak value at 3 mol% Sm3+. With doping Na+ or K+, the intensities are enhanced.

    Aug. 24, 2021
  • Vol. 39 Issue 5 913 (2010)
  • JIAO Yang, YIN Chun-hao, LIU Hai-shun, LIANG Ning, and BAI Qiu-fei

    Applying crystal field theory and irreducible representation method,the completely diagonalized Hamiltonian matrices of 3d2/3d8 ion configurations in the trigonal symmetry sites are established,which includes four kinds of microscopic magnetic interactions:spin-orbit interaction,spin-spin interaction,spin-other-orbit interaction and other orbit-other orbit interaction.The spectral fine structure,local structure and zero-field splitting parameters of V3+∶α-Al2O3 and Ni2+∶α-Al2O3 crystals are investigated as well as the influence of the doping.The results show that doping complementary ions can not change the fine structure of spectra and the symmetry of crystal structure but the spectral splits and local structure of crystal.The local structure stretch distortion in Ni2+∶α-Al2O3 is larger than that of V3+∶α-Al2O3 crystal while the angle change is less.

    Aug. 24, 2021
  • Vol. 39 Issue 5 918 (2010)
  • LIU Qing, XU Lu-ping, MA Yi-de, and SU Zhe

    In order to process multi-threshold image segmentation automatically,the traditional pulse coupled neural networks model is improved.A new algorithm of multi-threshold image segmentation using improved PCNN based on the maximization of mutual information is put forward according to the relationship between original image and segmented image,which is based on the optimization object of maximal of mutual information and a new measurement criterion for determining the number of clusters in an image called difference of mutual information.Theoretical analysis and simulation results indicate that the new method can automatically determine the optimal cyclic iterative times and the optimal number of gray-scale clusters,has a favorable capability to carve up characteristics and maintain the edges,texture and details of images,has higher precision in different image segmentation and can be more adaptability.

    Aug. 24, 2021
  • Vol. 39 Issue 5 923 (2010)
  • SHI Si-qi, SHI Guang-ming, CHEN Xu-yang, and LI Fu

    An object recognition algorithm based on segmented-smoothing contour is proposed.The contour is divided into two kinds of zones by curvature:feature zones and non-feature zones.Then,the different kinds of zones are smoothed with Gaussian functions with different variance.Finally,the object recognition algorithm based on affine moment-invariant is applied to recognize the smoothed contours.The simulation result shows the better contour-smoothing results and the significant improvement to recognition rate.

    Aug. 24, 2021
  • Vol. 39 Issue 5 929 (2010)
  • LI Jin-Xiang, ZHENG Shu-hong, YANG Ren-Er, and SHAO Jie

    To solve the error propagation of video transmission on unreliable networks,a new frame-based multiple description coding scheme with flexible redundancy insertion between descriptions via prediction is presented.To meet the varied environments of networks,several decode algorithms with various complexities and efficiency are also proposed.Simulation result shows that the presented method is demonstrated its adequate efficiency in preventing error propagation of video stream.And,the system is more robust in the case of packet-loss over different networks.

    Aug. 24, 2021
  • Vol. 39 Issue 5 935 (2010)
  • LI Chang-hua, and WANG Dong

    In order to speed up the mark matching under the condition of rotating and scaling,a method for shape matching based on sparse model is proposed using Hausdorff distance as the matching distance. This method has two stages:a sparse model is used in rough matching with a large distance threshold; a full model is used in precise matching with dual thresholds which are a moderately small distance threshold and a large coincidence rate threshold. An experiment is conducted,in which marks imposed on a map are tested,and shorter matching time is obtained with low false negative rate and low false positive rate. This method has been successfully used in military mark recognition in maps.

    Aug. 24, 2021
  • Vol. 39 Issue 5 941 (2010)
  • SUN Wei, GUO Bao-long, ZHU Juan-juan, and CHEN Long

    A general hierarchical particle filtering framework for designing an optimal proposal distribution is proposed. The essential idea is to augment a second filter′s estimate into the proposal distribution design. Based on this framework,a novel algorithm for robust and efficient visual tracking is given. The algorithm using hierarchical particle filtering procedures at each level and can efficiently extract high-confidence regions through video frames by exploiting the temporal consistency of region confidences. Comparisons with the mean shift tracker and a generic particle filter shows the advantages and limitations of the new approach.

    Aug. 24, 2021
  • Vol. 39 Issue 5 945 (2010)
  • ZENG Luan, ZHAO Zhong-wen, and TAN Jiu-bin

    In order to solve the problem that when the output data stream of a certain type of high resolution aerial camera reaches 200 megabytes per second,conventional methods are difficult to record the image data in real time,a self-starting,multi-channel hybrid synchronization direct-write method of SCSI hard disk is proposed.The new designed state controller optimizes the recording time series of the SCSI hard disk,so that multiple concurrent recording channels can generate separate direct-write pulses automatically according to the data cache and the status of the hard disk.The image data can be recorded on the hard disk with high speed and hybrid synchronization.Experimental results prove that the method can record the image data at the rate of 200 megabytes per second,storage capacity attained 280 Gigabytes,and moreover,the structure is simple and practical.

    Aug. 24, 2021
  • Vol. 39 Issue 5 951 (2010)
  • XU Shu-hua, and QI Ming-ming

    A methods using stationary wavelet transform based on multi-scales total least squares for image denoising is proposed.The noisy image is decomposited using stationary wavelet.For the high frequency components of image decomposition,the wavelet coefficients are estimated using total least squares.The interscale correlations of wavelet coefficients are considered.The multi-scales total least squares for estimating wavelet coefficients is proposed.Then the high frequency coefficients of signal are obtained.The denoised image is obtained through inverse wavelet transform.The experimental results show that the image can be denoised effectively based on total least squares using the interscale correlations of wavelet coefficients.The SNR and the visual quality are improved substantially.

    Aug. 24, 2021
  • Vol. 39 Issue 5 956 (2010)
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