Journals >Infrared and Laser Engineering
Contents
2005
Volume: 34 Issue 3
27 Article(s)
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Research Article
Effect of cloud on the target-background contrast
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Target-background contrast is one of the important parameters for indentification of target in space.Since cloud covers about 50% the ground surface and has important influence to the radiation transfer,it is necessary to taking into account the influence of cloud in the computing process of the target- background contTarget-background contrast is one of the important parameters for indentification of target in space.Since cloud covers about 50% the ground surface and has important influence to the radiation transfer,it is necessary to taking into account the influence of cloud in the computing process of the target- background contrast. In the paper, the effect of the optical properties of cloud on the target-background contrast is analyzed based on the plane parallel assumption and the probability of cloud free light of sight (PCFLOS)..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 281 (2005)
Dual-band IR image simulation based on 3D model
[in Chinese], [in Chinese], and [in Chinese]
Based on the output model data of Wavefront OBJ file, combined heat transfer model and infrared sensor model, infrared images based on 3D model with high details for the use of recognition algorithm are generated.The results meet the needs of Automated Target Recognition (ATR) system and provide rich and reliable IR imBased on the output model data of Wavefront OBJ file, combined heat transfer model and infrared sensor model, infrared images based on 3D model with high details for the use of recognition algorithm are generated.The results meet the needs of Automated Target Recognition (ATR) system and provide rich and reliable IR images for testing of ATR algorithm.Finally,the simulated images are presented under the platform of Microsoft Windows and Open GL with C++..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 287 (2005)
Multi-view modeling of 3-D target based on Zernike moments
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Modeling is an important step in 3-D target recognition. Avoiding the recovery of 3-D obje- ct, multi-view modeling is used widely in 3-D object modeling. Multiple 2-D views are obtained by proje- cting a tessellated regular polyhedron onto the viewing sphere.In order to describe all shape and pose info- rmation, a finModeling is an important step in 3-D target recognition. Avoiding the recovery of 3-D obje- ct, multi-view modeling is used widely in 3-D object modeling. Multiple 2-D views are obtained by proje- cting a tessellated regular polyhedron onto the viewing sphere.In order to describe all shape and pose info- rmation, a fine partition of the viewing sphere is necessary,which leads to computation complexity. Zernike moments have a rotation invariant property. A method is used to decrease the number of 2-D projections view by extracting the Zernike moments of each 2-D view, whose max order is decided by the difference between the original image and the reconstruction one.Those partitions with Zernike moments of correspon- ding views are similar are merged and a characteristic view is obtained for a new partition. Experimental results show the validity of the method..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 292 (2005)
Infrared scene simulation with image based rendering technique
[in Chinese], [in Chinese], and [in Chinese]
Infrared scene simulation can provide the necessary sample images for target recognition and tracking, and has very important meaning for algorithm's training, evaluation and reliability test. Infrared simulation based on geometric modeling is difficult to provide the realistic simulation effect. Moreover, its compInfrared scene simulation can provide the necessary sample images for target recognition and tracking, and has very important meaning for algorithm's training, evaluation and reliability test. Infrared simulation based on geometric modeling is difficult to provide the realistic simulation effect. Moreover, its computation is very large. The simulation method of infrared scene image with image based rendering (IBR) technique that is free of geometric modeling is proposed. According to the characteristic of infrared image, the nonlinear iteration algorithm for fundamental matrix computation and the dynamic programming stereo matching algorithm with feature constrains are proposed. The simulated images are more realistic because the reference images for simulation are real images. Furthermore, without intricate geometric modeling,the method can provide real time realization. The experiment result shows the method can produce realistic infrared images..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 297 (2005)
Numerical simulation of hard-edged diffracted beams
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the production and propagation of lasers there are more or less limiting apertures. There- fore, the beam propagation through hard-edged apertured optical systems is of practical importance, and a variety of simulation methods have been developed. As usual, the direct numerical integration of the Collins formula proIn the production and propagation of lasers there are more or less limiting apertures. There- fore, the beam propagation through hard-edged apertured optical systems is of practical importance, and a variety of simulation methods have been developed. As usual, the direct numerical integration of the Collins formula provides an exact simulation method, but it becomes very cumbersome and time consumi-ng as the number of apertures increases. In this paper four concise methods, i.e., the analytical propa- gation equation, recurrence algorithm, complex Gaussian function expansion and matrix representation have been used to simulate hard-edged diffracted beams. Their advantages and applicable range are analyzed and some improvements are discussed..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 301 (2005)
Modeling on ultrashort intense laser pulses propagation in the atmosphere
[in Chinese], and [in Chinese]
The propagation of ultrashort,intense laser pulses in the atmosphere have many important applications in the fields such as remote sensing, electronic countermeasures, and induced electric discharges. It has been theoretically analyzed.The linear and nonlinear effects, such as dispersion, nonlinear self-focusing, stimuThe propagation of ultrashort,intense laser pulses in the atmosphere have many important applications in the fields such as remote sensing, electronic countermeasures, and induced electric discharges. It has been theoretically analyzed.The linear and nonlinear effects, such as dispersion, nonlinear self-focusing, stimulated Raman scattering, multiphoton and tunneling ionization, pulse energy depletion due to ionization, relativistic focusing,and ponderomotively excited plasma wakefields, are discussed. A set of equations describing ultrashort, intense laser pulses propagation in the atmosphere is given, and the equations provide a basis for the future study..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 306 (2005)
Design of FIFO applied in the ASIC chip of image processing based on multilevel filter
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The architecture of the multilevel filter ASIC chip used for image processing is described.There are one input FIFO and three output FIFO controlled by the control module to realize multiplex image data real time processing and transferring efficiently. Considering FIFOs′ design and application in the chip, one asynchrThe architecture of the multilevel filter ASIC chip used for image processing is described.There are one input FIFO and three output FIFO controlled by the control module to realize multiplex image data real time processing and transferring efficiently. Considering FIFOs′ design and application in the chip, one asynchronous FIFO buffers and stores input data to match datapath to slower data import; three synchronous FIFOs are designed separately as buffer storages of image processing data from three level filter ,whose templates are separately 1×3?1×5(equates to the cascade connection of two 1×3 templates)and 1×7(equates to the cascade connection of three 1×3 templates).The three FIFOs occupy an output data bus by the way of time-sharing.Simulation results indicate that the design is right and effective..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 348 (2005)
Embedded image coding algorithm for hardware implementation
[in Chinese], [in Chinese], and [in Chinese]
EZBC algorithm combines the advantages of zeroblock/zerotree coding and context modeling of the subband/wavelet coefficients by utilizing the correlation of inter-band and intra-band. In EZBC, the sophisticated context models were designed for coding quadtree nodes at different levels and subbands. Thus,EZBC outperformEZBC algorithm combines the advantages of zeroblock/zerotree coding and context modeling of the subband/wavelet coefficients by utilizing the correlation of inter-band and intra-band. In EZBC, the sophisticated context models were designed for coding quadtree nodes at different levels and subbands. Thus,EZBC outperforms SPHIT and can be competitive with EBCOT in compression efficiency. But a large amount of memory is required to maintain two lists that are used to store the coordinates of the quadtree nodes needed to be coded, also a great amount of operations to read and write the memory are required in each coding pass. These become drawbacks for a hardware implementation. An improved EZBC algorithm based on zeroblock and quadtree, with low complexity and high performance is presented in this paper. The improved algorithm utilizes the significance state table of bitplane nodes and the context look-up table to complete the coding passes and form the context, the comparison reveals that the PSNR results of the proposed algorithm are nearly the same performance as that of EZBC,furthermore,the algorithm requires low money and reduces the implementation complexity..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 352 (2005)
Design of scanning control with VHDL
[in Chinese]
In this paper, VHDL is applied to design the scanning system of LIDA. The MAX7000 series is selected to achieve the function. Due to the application of the VHDL and the Complex Programmable Logic Device(CPLD), the system complexity and design difficulty are reduced and the efficiency is enhanced. Some source codes are In this paper, VHDL is applied to design the scanning system of LIDA. The MAX7000 series is selected to achieve the function. Due to the application of the VHDL and the Complex Programmable Logic Device(CPLD), the system complexity and design difficulty are reduced and the efficiency is enhanced. Some source codes are presented in the paper, which have been synthesized and simulated. At last,questions during the design are emphasized and analyzed..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 356 (2005)
Design of special processor for wireless fuse solid target video frequency echo simulator based on FPGA
[in Chinese], [in Chinese], and [in Chinese]
In this paper, a special processor for wireless fuse solid target video frequency echo simulator has been designed based on FPGA.This plan sufficiently utilizes the optimal technology which suits for the FPGA′s structure and resolve the bottleneck in the high-speed mode. Experimental result proves that the processor haIn this paper, a special processor for wireless fuse solid target video frequency echo simulator has been designed based on FPGA.This plan sufficiently utilizes the optimal technology which suits for the FPGA′s structure and resolve the bottleneck in the high-speed mode. Experimental result proves that the processor has not only the high-speed performance of ASIC circuit, but also the flexibility of the DSP. The test result satisfies the system′s request..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 360 (2005)
Design and realization of FOG source's driving circuit with low power dissipation
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the request of fiber-optic gyro (FOG) on the driving circuit of light source, thepower driving circuit with high precision control is designed. In addition to the power dissipation being saved,the heat radiation and the size of the driving circuit is also reduced greatly. A driving circuit with high precision,Based on the request of fiber-optic gyro (FOG) on the driving circuit of light source, thepower driving circuit with high precision control is designed. In addition to the power dissipation being saved,the heat radiation and the size of the driving circuit is also reduced greatly. A driving circuit with high precision, low power dissipation and small minimized size is realized.Test results are available..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 364 (2005)
Development of a laser diode driver based on FPGA
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new continue wave laser diode driver,which integrates FPGA technique, with high quality single-chip microcomputer (SCM) HD64F7045 as the controlling center is presented. In the LD controller module, the use of negative feedback technique could stabilize the drive current (IF), the optical output power (Po) and the foA new continue wave laser diode driver,which integrates FPGA technique, with high quality single-chip microcomputer (SCM) HD64F7045 as the controlling center is presented. In the LD controller module, the use of negative feedback technique could stabilize the drive current (IF), the optical output power (Po) and the forward voltage (VF) respectively with high stability.The complete laser diode protection is provided by means of independent current limit and power limit settings, output off shorting circuits, and a slow turn on sequence. In the temperature controller module, the temperature could be controlled precisely with PI control method and the thought of integral separation. Results show that forward current stability can attain 10-4 degree, and temperature stability can attain ±0.01 ℃..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 368 (2005)
Effect of heat treatment on the crystallization of Nd:YAG ceramics
[in Chinese], and [in Chinese]
The(Y0.99Nd0.01)3Al5O12 nano-sized powders were synthesized by low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by cheThe(Y0.99Nd0.01)3Al5O12 nano-sized powders were synthesized by low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by chemical precipitation method. The powders were characterized by TG-DTA, XRD,FT-IR and TEM, respectively. The crystallite sizes were calculated by Scherrer's formula using the full width at half maximum of YAG(420) diffraction lines. The study focused on the crystallization of ceramics with different heat treatment temperatures. The experiments show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by LCS is in the range of 20～50 nm depending on the thermal treatment temperature. With the temperature increasing, the mean grain sizes ascend, the stand deviations keep at about 2.0 and crystal lattices decrease. The grains grows mainly by the grain boundary diffusion.The lattice parameter expansion is caused by an increase of repulsive dipolar interaction at the surface of particles..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 373 (2005)
[in Chinese]
Latest development and application market of uncooled thermal imaging
[in Chinese], [in Chinese], and [in Chinese]
The latest development, research trend and the application market of uncooled thermal ima- ging are summarized. The ferro electrical focal plane array and the microbolometer focal plane array have been the main uncooled imaging devices. The annual yield of the former has increased 11.4% and the latter 32.4%.Uncooled thThe latest development, research trend and the application market of uncooled thermal ima- ging are summarized. The ferro electrical focal plane array and the microbolometer focal plane array have been the main uncooled imaging devices. The annual yield of the former has increased 11.4% and the latter 32.4%.Uncooled thermal imaging technology has advantage over dark imaging on the range and has advantage over cooled thermal imaging on the dimension and cost which make it main power on the middle range detection. It will take the place of cooled thermal imaging in many applications in the near future..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 257 (2005)
Scene-based statistical algorithms for nonuniformity correction of infrared images
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Scene-based statistical algorithms for nonuniformity correction assume the distribution of scene value to estimate the mean and variance of infrared energy received by each detector, then estimate the response parameters of each detector. In this way nonuniformity can be corrected. Current scene statistical algorithms Scene-based statistical algorithms for nonuniformity correction assume the distribution of scene value to estimate the mean and variance of infrared energy received by each detector, then estimate the response parameters of each detector. In this way nonuniformity can be corrected. Current scene statistical algorithms for nonuniformity correction are analyzed. Interacting multiple model (IMM) is applied to correct nonuniformity. The experimental result shows that even taking consecutive frames as observing data, the nonuniformity can be corrected satisfactorily using IMM algorithm. It extends the applicability of Kalman filtering. More simulations for other algorithms have been done,and results indicate that the IMM algorithm has a better convergent performance..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 261 (2005)
Dual band IR small target fusion detection using the D-S evidence theory
[in Chinese], [in Chinese], and [in Chinese]
Aim at the problem of detecting for distant small target with very low SNR,a method of two color IR small target fusion detection using D-S evidence theory is proposed. The algorithm firstly detects targets from each sensor using statistics detection method and fuses the results using "OR" logic to reduce theAim at the problem of detecting for distant small target with very low SNR,a method of two color IR small target fusion detection using D-S evidence theory is proposed. The algorithm firstly detects targets from each sensor using statistics detection method and fuses the results using "OR" logic to reduce the probability of being missed.Then extracts the multiple image features of these target candidate areas in fusion detection result from the two sensor images as the evidence to eliminate false detection.Finally, distinguishes the false target from real target using the D-S evidence theory based on multiple features, and sends the recognition result to the target detection output of the whole system..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 266 (2005)
Application of the quantum interference effect in designing energy band structure of the infrared photodetector
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The electronic states of GaAs/AlxGa1-xAs superlattices are calculated by the quantum interference effect. Compared with the K-P method, it is found that the results of two methods are accordance with the increase of the barrier width. This indicates the new method is suitable for calculating the electronic states of suThe electronic states of GaAs/AlxGa1-xAs superlattices are calculated by the quantum interference effect. Compared with the K-P method, it is found that the results of two methods are accordance with the increase of the barrier width. This indicates the new method is suitable for calculating the electronic states of superlattice with the wider barrier,and is easier to manipulate than the K-P method. In addition, the photocurrent spectrum of superlattice sample is analyzed by two methods. As a result, the data given by the new method is closer to the experimental results than that by the K-P method. This confirms that the electronic states caused by the quantum interference effect exist in superlattice, and the new method can be applied to design energy band structure of the infrared photodetector..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 272 (2005)
Placement of the array detectors of 45° multi-parallel scanning
[in Chinese], [in Chinese], and [in Chinese]
In the system of 45° multi-parallel scanning,the position of the wave bands on the focal plane will effect the scanning result directly. The influence of the detector number of wave band and the position of the wave bands on the result is studied.The aberrance degree of scanning image aroused by the change of the In the system of 45° multi-parallel scanning,the position of the wave bands on the focal plane will effect the scanning result directly. The influence of the detector number of wave band and the position of the wave bands on the result is studied.The aberrance degree of scanning image aroused by the change of the parameter is analyzed.In the end,the demand of placing the detector is presented..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 277 (2005)
[in Chinese]
Real-time image tracking system for moving targets by CCD
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The real-time image tracking system based on the DSP (TMS320C6415) for moving targets using charge coupled plane array imaging device (CCD) is discussed.The principle diagram and block diagram is given,and the image acquisition and image processing system are discribed.The momentpreserving thresholding method and the aThe real-time image tracking system based on the DSP (TMS320C6415) for moving targets using charge coupled plane array imaging device (CCD) is discussed.The principle diagram and block diagram is given,and the image acquisition and image processing system are discribed.The momentpreserving thresholding method and the adaptive thresholding method based on gradient are used to pick up targets, and the mass centroid tracking algorithm based on orthogonal projection and linear-fitting predicting approach are used to track targets. The experimental results show that the algorithm is feasible and practical..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 310 (2005)
Structure based airport recognition in remote sensing image
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on analyzing line structure of runway,a new method to automatically detect runways in remote sensing image is presented.Firstly, line structure of the image by mathematical morphology is extracted.Then straight-line is grouped through dynamic clustering.Finally lines are relinked and runway are paired. Through ruBased on analyzing line structure of runway,a new method to automatically detect runways in remote sensing image is presented.Firstly, line structure of the image by mathematical morphology is extracted.Then straight-line is grouped through dynamic clustering.Finally lines are relinked and runway are paired. Through runway′s localization, the recognition of airfield is realized.The experimental results show that this method has a perfect performance and usability to identify airfield of remote sensing images..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 314 (2005)
Template-matching method based on image texture
[in Chinese], [in Chinese], and [in Chinese]
To improve real-time performance of image registration and enhance robust performance of target tracking under the complex scene, a novel template-matching method based on image region texture is presented. Binary texture matrixes of horizontal and vertical direction were constructed according to gray direction of neigTo improve real-time performance of image registration and enhance robust performance of target tracking under the complex scene, a novel template-matching method based on image region texture is presented. Binary texture matrixes of horizontal and vertical direction were constructed according to gray direction of neighborhood pixels, and then the similarity measurement criterion was defined to measure correlation credibility between binary texture matrixes of each dimension. The correlation credibility of appointed object was obtained through combination of two-direction registration result at last. Experiments prove that the proposed algorithm is robust for image illumination variance and target partial occlusion..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 319 (2005)
Adaptive enhancement of object image influenced by cloud and fog
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
For the influence of fog and cloud on the satellite images, the object images have a rapid descent in contrast and distinguishability. Pointing at the influence,an adaptive algorithm of object image is brought forward to overcome the degradation. The experimental result clearly shows that the algorithm has a stong adapFor the influence of fog and cloud on the satellite images, the object images have a rapid descent in contrast and distinguishability. Pointing at the influence,an adaptive algorithm of object image is brought forward to overcome the degradation. The experimental result clearly shows that the algorithm has a stong adaptability,improves the contrast of the object images influenced by cloud and fog,keeps the contrast and brightness of the non-effect part and achieves the object of adaptive enhancement..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 324 (2005)
Image fusion algorithm based on wavelet transform
[in Chinese], [in Chinese], and [in Chinese]
An improved image fusion algorithm based on wavelet transform is presented. The image is decomposed into high-frequency image and low-frequency image.The maximum absolute value within the window of high-frequency image is used as an activity measure associated with the center pixel to get the fused high-frequency imageAn improved image fusion algorithm based on wavelet transform is presented. The image is decomposed into high-frequency image and low-frequency image.The maximum absolute value within the window of high-frequency image is used as an activity measure associated with the center pixel to get the fused high-frequency image. The quality of the blocks within the low-frequency image is measured to determine the fused low-frequency image. The experimental result shows that clarity and contrast of the fused image are improved. The proposed algorithm is verified effective for image fusion..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 328 (2005)
Regularization method for SAR image enhancement in amplitude domain
[in Chinese], [in Chinese], and [in Chinese]
Regularization technique could enhance SAR(Synthetic Aperture Radar) image by imposing prior information. In this paper, firstly,the prior information in existence is analyzed, a feature-enhanced SAR image formation technique based on regularization in amplitude domain is proposed, it is proved that the results are equRegularization technique could enhance SAR(Synthetic Aperture Radar) image by imposing prior information. In this paper, firstly,the prior information in existence is analyzed, a feature-enhanced SAR image formation technique based on regularization in amplitude domain is proposed, it is proved that the results are equivalent in the complex data domain and in the amplitude domain, further the phase holding property is explained, and the efficiency of the algorithm is improved. Secondly,an easily realized technique to determine parameter is descriked,which can effectively suppress the noise and protect the object.Finally,the experimental results of the simultion and MSTAR(Moving and Stationary Target Acquisition and Recognition) images show that the algorithm is effective..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 333 (2005)
High resolution image by DBS with SAR/GMTI
[in Chinese], [in Chinese], and [in Chinese]
Doppler beam sharpening(DBS)technique can provide reference for the location of the moving target detected to attack more accurately and effectively. DBS also can be used in trajectory navigation, landform matching, etc. In this paper, the basic theory of DBS imaging is introduced at first, then SAR processing method iDoppler beam sharpening(DBS)technique can provide reference for the location of the moving target detected to attack more accurately and effectively. DBS also can be used in trajectory navigation, landform matching, etc. In this paper, the basic theory of DBS imaging is introduced at first, then SAR processing method is analyzed which includes range cell migration correction technique and azimuth dechirping technique,and can improve image quality effectively in DBS imaging on SAR/GMTI mode. At last, some satisfying images by DBS based on the raw radar data are obtained..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 337 (2005)
Video shot segmentation and key frame extraction based on clustering
[in Chinese], [in Chinese], and [in Chinese]
Shot segmentation is a vital technology that must be resolved firstly in video retrieval and browse. Then key frame extraction will be carried out after shot segmentation to describe main content of shot. An improved algorithm for shot segmentation and key frame extraction based on clustering is proposed, a referenced Shot segmentation is a vital technology that must be resolved firstly in video retrieval and browse. Then key frame extraction will be carried out after shot segmentation to describe main content of shot. An improved algorithm for shot segmentation and key frame extraction based on clustering is proposed, a referenced variable is used in unsupervised clustering to resolve the frame sequence's incontinuity or false segmentation problems which can be caused probably by unsupervised clustering. During key frame extraction, the concept of image entropy is used after shot being segmented into sub-shots. Experimental results demonstrate the efficiency of the improved algorithm in shot segmentation and key frame extraction..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 341 (2005)
Encrypting optical image based on compound encoding on space-fractional domain
[in Chinese], [in Chinese], and [in Chinese]
For the improvement of security capability of existing optical security system, a novel method for encrypting optical image using encoding on both space domain and fractional Fourier domain is presented. In this paper, image is Fresnel transformed and Fractional Fourier transformed successively, and phase encoding is iFor the improvement of security capability of existing optical security system, a novel method for encrypting optical image using encoding on both space domain and fractional Fourier domain is presented. In this paper, image is Fresnel transformed and Fractional Fourier transformed successively, and phase encoding is implemented in both Fresnel domain and Fractional Fourier domain. The parameters in two transform can be designed as keys, and the wavelength-key can also be introduced into the encryption process successfully, then the keys of the security system are set on different domains, which can improve the security capability of the system. Computer simulation indicates that the method proposed in this paper can encrypt and decrypt image successfully, and the decrypted results are very sensitive to the keys, people unauthorized can hardly decrypt the image correctly without knowing them..
Infrared and Laser Engineering
- Publication Date: Jun. 01, 2005
- Vol. 34, Issue 3, 345 (2005)
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