Journals >Infrared and Laser Engineering
Contents
2003
Volume: 32 Issue 6
26 Article(s)
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Research Article
Overview of simulation test system used for photoelectronic countermeasure
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Firstly, the purpose and the significance of developing simulation test system used for photoelectronic countermeasure are discussed. Secondly, the actuality and the development of domestic and foreign simulation test systems used for photoelectric weapons are expatiated, and the general composition of simulation test Firstly, the purpose and the significance of developing simulation test system used for photoelectronic countermeasure are discussed. Secondly, the actuality and the development of domestic and foreign simulation test systems used for photoelectric weapons are expatiated, and the general composition of simulation test system used for photoelectronic countermeasure is introduced. Finally, the routine test content and the test flow of photoelectric weapons are simply given, and the methods that may be used for the simulation test are discussed..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 551 (2003)
Optical fiber-based simulation system for laser fuze
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Laser fuze is a kind of proximity fuze generally used in guided weapon. However, it is very difficult to obtain the intensity of reflected laser pulses at the receiver's windows in the laboratory. In addition, testifying the signal processing algorithm in the laboratory is another problem. A method of optical fiberLaser fuze is a kind of proximity fuze generally used in guided weapon. However, it is very difficult to obtain the intensity of reflected laser pulses at the receiver's windows in the laboratory. In addition, testifying the signal processing algorithm in the laboratory is another problem. A method of optical fiber-based simulation system is proposed here for laser fuze. Firstly, coupling lens and auto-focus lens are used in this system to couple the laser beam transmitted from (emitter) into fiber. Then, real-time power attenuation simulation is realized by means of a program-controlled wideband intensity attenuator. After being attenuated, the optical signals returned to windows of receiver through coupling lens by fiber optic propagation. In the system , the fiber is used to propagate laser pulses, so it can accurately simulate the reflective laser signalwhich laser fuze has transmitted such as passing across the target. At the same time, it can testify the signal processing algorithm used in laser fuze in the laboratory through controlling attenuation of laser signal in real-time.By theoretical analysis,system composition and detailed design of every part are proposed,then the design is verified by conclusion..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 556 (2003)
Modeling and simulation analysis of ICCD camera
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The modeling of ICCD camera is an important problem to simulate image of ICCD camera, optimize the design and improve system capability.Depending on the physical structrure, a full physical modeling of dynamic response which takes into account real struction and parameters such as noise is developed. The system capabilThe modeling of ICCD camera is an important problem to simulate image of ICCD camera, optimize the design and improve system capability.Depending on the physical structrure, a full physical modeling of dynamic response which takes into account real struction and parameters such as noise is developed. The system capability of ICCD camera working on typical condition is also simulated and analyzed..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 560 (2003)
One-dimensional equivalent circuit model analysis for IR GaAs liquid crystal light valve
The working principle and basic structures of IR GaAs liquid crystal light valve are described and the one-dimensional equivalent circuit model for IR GaAs liquid crystal light valve is constructed. According to above model, the influence of thickness of photo semiconductor layer-GaAs on the dynamic modulating range anThe working principle and basic structures of IR GaAs liquid crystal light valve are described and the one-dimensional equivalent circuit model for IR GaAs liquid crystal light valve is constructed. According to above model, the influence of thickness of photo semiconductor layer-GaAs on the dynamic modulating range and driving frequency and resolution of IR liquid crystal light valve has been analyzed. The relevant curves and the optimal thickness range of GaAs have been given. The structure parameters of liquid crystal light valve are calculated accordingly and the liquid crystal light valve is redesigned and a part of experimental results is given..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 564 (2003)
Infrared image generation system based on signal injection
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In the generation of infrared image, a method based on signal injection is presented in order to attain a high performance-price ratio. It consists of six interacting modules. The radiance of target, background and interference arrives at the sensor after it is attenuated by the atmosphere. The radiance and attenuationIn the generation of infrared image, a method based on signal injection is presented in order to attain a high performance-price ratio. It consists of six interacting modules. The radiance of target, background and interference arrives at the sensor after it is attenuated by the atmosphere. The radiance and attenuation of the atmosphere are computed with the LOWTRAN model. With the mathematical model of the sensor, the scaling principle of converting the radiance to the gray-scale is built. The whole 3D scene is rendered with OpenGL. By this system, the ability of recognizing and tracking target can be evaluated in the laboratory. Therefore the outfield experiments can be reduced..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 568 (2003)
Research on all fiber optic Fourier flat-top Interleaver
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The transmission function of the Interleaver consisting of two cascaded unbalanced Mach-Zehnder interferometer is analyzed. Based on the Fourier series digital approximation method and trapezium wave which is utilized to simulate the output waveshape, the optimal parameter of the Interleaver has been studied.This kind The transmission function of the Interleaver consisting of two cascaded unbalanced Mach-Zehnder interferometer is analyzed. Based on the Fourier series digital approximation method and trapezium wave which is utilized to simulate the output waveshape, the optimal parameter of the Interleaver has been studied.This kind of Interleaver has flat pass band and broad cut band, so it's stability and isolation are improved greatly. The Interleaver is also studied in experiment. The theoretical results are consistent with the experimental results..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 583 (2003)
Practical broadband analog fiber optic transmission system
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A practical broadband analog fiber optic transmission system based on the laser diode direct modulation characteristic is reported. Its configuration and measured performance are described. The measured results indicate that -3 dB bandwidth of the system is 30 kHz～1.1 GHz, the dynamic range is no less than 40 dB withinA practical broadband analog fiber optic transmission system based on the laser diode direct modulation characteristic is reported. Its configuration and measured performance are described. The measured results indicate that -3 dB bandwidth of the system is 30 kHz～1.1 GHz, the dynamic range is no less than 40 dB within the nonlinearity of ±5% and the peak-to-peak amplitude of output noise is less than 5 mV. The system has many advantages, such as wide bandwidth, large dynamic range, low output noise and strong immunity to electromagnetic interference. It is suitable for the sub-nanosecond signal transmission in the complicated electromagnetic environment..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 587 (2003)
Automatic detection method of IR small target in complex sea background
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The proposed approach adopts adaptive filter to suppress random noise and Gauss's noise so as to enhance the SNR. Then, Otus's threshold method is used to segment the image and locate the sea-sky-line, through which the target potential area can be determinated. A mathematical morphology filter, Top-Hat operatoThe proposed approach adopts adaptive filter to suppress random noise and Gauss's noise so as to enhance the SNR. Then, Otus's threshold method is used to segment the image and locate the sea-sky-line, through which the target potential area can be determinated. A mathematical morphology filter, Top-Hat operator, is employed to execute filtering to restraint the background contribution and maintain the small target in high brightness area. By choosing proper structural element, an open filter is executed to discard small false alarms. Eventually, the real small target can be segmented through searching maximal value in the target potential area nearby the sea-sky-line and assigning threshold. The experimental results show that the method can reject the clutter caused by waves and clouds and effectively detect and segment IR small target in the complicated sea background..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 590 (2003)
Knowledge-based airport extraction in radar images
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In order to extract airports from the lower SNR radar images reliably, the knowledge about radar imaging is used to post procession of the results of Radon transform. A simple and efficient way is given to find the end points of line features and a kind of distance transform rule is given to weight the similarity of thIn order to extract airports from the lower SNR radar images reliably, the knowledge about radar imaging is used to post procession of the results of Radon transform. A simple and efficient way is given to find the end points of line features and a kind of distance transform rule is given to weight the similarity of the extracted line features and the real line features. The experimental result shows that this method is effective on extracting airports from radar images..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 594 (2003)
Research on face recognition method based on holistic facial features
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Based on the analysis of principle and limitation of traditional holistic face recognition methods, EFM(Enhanced Fisher Model) is put forward. The face recognition experiment based on EFM shows promising result, because it has higher recognition rate than those based on PCA or FLD, especially suitable for the recognitiBased on the analysis of principle and limitation of traditional holistic face recognition methods, EFM(Enhanced Fisher Model) is put forward. The face recognition experiment based on EFM shows promising result, because it has higher recognition rate than those based on PCA or FLD, especially suitable for the recognition task in large face database..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 599 (2003)
New method of interior boundary of iris location based on active contour
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The key problem in iris recognition is how to locate iris's position in an image. A new method of interior boundary of iris location based on active contour is presented. Firstly, a point in pupil called pseudo-center, which isn't required to be located at the real center of pupil, is detected by a method of grThe key problem in iris recognition is how to locate iris's position in an image. A new method of interior boundary of iris location based on active contour is presented. Firstly, a point in pupil called pseudo-center, which isn't required to be located at the real center of pupil, is detected by a method of gray projection. Secondly, several points spaced evenly around the pseudo-center are chosen as initial snake, and then the snake evolves until it gets the interior boundary of iris. Finally, two values are computed --one is the real center of pupil, which is expressed through the center of snake, and the other is the radius of pupil, the average distances between every control point of snake and the center. Experiments show that our method has better performance in speed and precision than Hough transform and daugman method. Moreover, our method is more robust because the pseudo-center is not rigorous..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 605 (2003)
Study on AlxGa1-xAs selective wet oxidation technology
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The wet oxidation of buried AlxGa1-xAs was investigated. The oxidation character and the dependence of oxidation rate on the temperature and Al content have been studied in details. Through analyzing oxidation mechanism and linear relationship between oxidation length and time, it is educed that the lateral oxidation oThe wet oxidation of buried AlxGa1-xAs was investigated. The oxidation character and the dependence of oxidation rate on the temperature and Al content have been studied in details. Through analyzing oxidation mechanism and linear relationship between oxidation length and time, it is educed that the lateral oxidation of AlxGa1-xAs, in relatively short oxidation time, is a reaction rate limit process. Based on the optimized parameters extracted, VCSEL with 8 μm oxidation aperature was produced, whose maximum optical power output is 3.2 mW, wavelength is 978 nm and driving current is 15 mA..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 647 (2003)
Etching study of micro-cavity with flexible film of novel infrared detector
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Pneumatic infrared detector based on gas direct absorption and MEMS technology is a novel infrared detector for mid-far band uncooled infrared detection. Etching study of the key structure,micro-gas-cell and flexible film, is of great importance to device fabrication. Etching requirements for those structures are givenPneumatic infrared detector based on gas direct absorption and MEMS technology is a novel infrared detector for mid-far band uncooled infrared detection. Etching study of the key structure,micro-gas-cell and flexible film, is of great importance to device fabrication. Etching requirements for those structures are given and optimal EPW wet etching condition and speed are obtained through experiments, which insure controllability and good quality of device structure..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 651 (2003)
Implementation of inserting DVB Service Information tables into TS streams
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The purpose of DVB Service Information(SI) tables is discussed in detail. The interface to insert DVB SI tables into TS streams is designed and implemented in SDTV encoder system. Various SI tables can be inserted into TS streams using this interface in different applications. Then, services such as EPG and VOD could bThe purpose of DVB Service Information(SI) tables is discussed in detail. The interface to insert DVB SI tables into TS streams is designed and implemented in SDTV encoder system. Various SI tables can be inserted into TS streams using this interface in different applications. Then, services such as EPG and VOD could be provided by the SDTV encoder system. System is measured by stadard test instrument and compliant with DVB..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 655 (2003)
[in Chinese]
Approach of athermalizing infrared optical systems
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The active athermalizing technique used usually in our country and the passive athermalizing technique adopted successfully overseas are described. Considering domestic conditions, the possibility of introducing the passive athermalizing is discussed from three ways, matching optical material used in the system that isThe active athermalizing technique used usually in our country and the passive athermalizing technique adopted successfully overseas are described. Considering domestic conditions, the possibility of introducing the passive athermalizing is discussed from three ways, matching optical material used in the system that is all composed of spherical surfaces, using an aspherical surface and using a simple mechanical framework. Furthermore, the conclusions are given by design of a example and analysis of a great deal of data. In addition, infrared optical material, which is suitable for thermal imaging in our country now, is described..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 572 (2003)
Imaging circuit of UFPA helmet based on SOC design
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The principle of 320×240 UFPA helmet imaging circuit is discussed. The method of design based on SOC is introduced. Furthermore the block diagram for FPGA is given in this paper. On the basis of analysis of the structure of UFPA helmet imaging circuit, the key problems for the A/D converter, NUC and liquid crystalThe principle of 320×240 UFPA helmet imaging circuit is discussed. The method of design based on SOC is introduced. Furthermore the block diagram for FPGA is given in this paper. On the basis of analysis of the structure of UFPA helmet imaging circuit, the key problems for the A/D converter, NUC and liquid crystal display controller are introduced. Main driving timing sequences are simulated. The simulation result demonstrates the validity of the design of UFPA helmet imaging circuit based on SOC using FPGA..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 577 (2003)
Study on the purity of p-diethylbenzene using near infrared spectroscopy
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Linear regression is used to analyse the NIR spectra (750～2 500 nm) of p-diethylbenzene to determine its purity. This method will greatly reduce the time and expenditure in detecting the sample, and make the synthesizing process of p-diethylbenzene more easy. Compared the results of near-infrared spectra with those of Linear regression is used to analyse the NIR spectra (750～2 500 nm) of p-diethylbenzene to determine its purity. This method will greatly reduce the time and expenditure in detecting the sample, and make the synthesizing process of p-diethylbenzene more easy. Compared the results of near-infrared spectra with those of gas chromatogram, it shows that in the wavenumber of 5 835 cm~(-1) the maximum related coefficient (0.992 9) is reached and the average prediction relative error is 2.72%. All results prove the practicability of this method discussed in this paper..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 580 (2003)
[in Chinese]
Statistical analysis for infrared image of the sky near the ground
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The infrared image of the sky near the ground is analyzed statistically.The mean of gray level, variance, horizontal and vertical scanning line, histogram of long-wave(8～12 μm)infrared images of the sky near the ground are analyzed. The images consist of 100% sunny, 100% cloudy, cloudy and night. Result about the analyThe infrared image of the sky near the ground is analyzed statistically.The mean of gray level, variance, horizontal and vertical scanning line, histogram of long-wave(8～12 μm)infrared images of the sky near the ground are analyzed. The images consist of 100% sunny, 100% cloudy, cloudy and night. Result about the analysis is also given. The relation between gray level mean and atmospheric temperature is linear. The variance of 100% cloudy sky image is small. Gray level linearly changes in vertical scanning line and keeps stable in horizontal scanning line. The histogram of image depends on the weather and time..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 610 (2003)
Restoration of high resolution image based on Gibbs model
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During the image restoration, choosing a proper model that describes the image is the key of restoration. A MAP framework based on Gibbs to extract a single super resolution image from image sequences is proposed. Additional novel observation data can be obtained and the feasible solution space is constrained with apriDuring the image restoration, choosing a proper model that describes the image is the key of restoration. A MAP framework based on Gibbs to extract a single super resolution image from image sequences is proposed. Additional novel observation data can be obtained and the feasible solution space is constrained with apriori assumptions on the form of the solution. Experimental results are provided to illustrate the performance of the algorithm that is better and faster than others..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 613 (2003)
Image feature segmentation method of color document based on rough set
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An algorithm to segment color document images into four different classes--background, photograph, text and graph is developed. By use of a modified RGB-ellipse color model, several features from the histogram of high-frequency wavelet transformed sub-bands are got to classify the color document image into the accordinAn algorithm to segment color document images into four different classes--background, photograph, text and graph is developed. By use of a modified RGB-ellipse color model, several features from the histogram of high-frequency wavelet transformed sub-bands are got to classify the color document image into the according regions guided by the rough set theory. The simulation shows that its performance in segmenting color document image is perfect..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 617 (2003)
Segmentation method of infrared image based on statistical model
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A new statistical model for infrared image is presented, which combined Gauss-pdf and generalized Gamma-pdf. The statistical moments of the model has closed form expressions. Models in common use also can be derived from it when the parameters are set to some specific values, so in this aspect it's generalized formA new statistical model for infrared image is presented, which combined Gauss-pdf and generalized Gamma-pdf. The statistical moments of the model has closed form expressions. Models in common use also can be derived from it when the parameters are set to some specific values, so in this aspect it's generalized form of the statistical model for infrared image. The estimation of parameters can be done via the statistical moments. Furthermore, the infrared image can be segmented properly based on the model..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 620 (2003)
Correlation trackingusing a novel distance measurement as feedback
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Template matching by means of correlation is common practice in object tracking. However, its sensitivity to deformations of the patterns and the broad unsharp peaks are significant drawbacks. To reduce the influence of the noise and occlusion, a novel distance measurement method is proposed, in which first order statiTemplate matching by means of correlation is common practice in object tracking. However, its sensitivity to deformations of the patterns and the broad unsharp peaks are significant drawbacks. To reduce the influence of the noise and occlusion, a novel distance measurement method is proposed, in which first order statistics of the close points between the template and the image are used as a matching measurement. Instead of computing the distance of the gray value of the two images, it counts the number of the close pixel pairs in the object image and the template. The correlation curve got in this way is proved to be much sharper and the matching precision is improved significantly. When above method is applied to the processing of tracking, the reasonable update of the template will be the key. Based on above similarity measurement method, an adaptive template updating strategy is also presented, which is capable of selectively updating the correlation template in response to the changes in an image sequence and enable the correlation to track target under serious background clutter while decreasing the risk of template drift..
Infrared and Laser Engineering
- Publication Date: Apr. 28, 2006
- Vol. 32, Issue 6, 624 (2003)
Measurement of disparity based on sparse-to-dense matching approach
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Image matching belongs to constrained optimization problems. Whether the system would converge to the global optimum is still an open problem. To produce smooth and detailed disparity map, three assumptions--uniqueness, continuity and ordering--are generally adopted. However, if a point appears in one image but it is oImage matching belongs to constrained optimization problems. Whether the system would converge to the global optimum is still an open problem. To produce smooth and detailed disparity map, three assumptions--uniqueness, continuity and ordering--are generally adopted. However, if a point appears in one image but it is occluded in the other one, above assumptions are invalid. While the unwanted smoothing occurs in the resultant disparity map, a surface with high intensity variation extends into neighboring surfaces with less variation across occluding boundaries. This fact creates the phenomena of so-called fattening and shrinkage of a surface. Therefore, when considering the definition of criteria for an optimal match in one matching algorithm, some other matching constraints must be imposed based on the internal image information, to ensure the global accurate matching results accompanied with occlusion detection. A sparse-to-dense matching approach is presented, which utilizes the energy map to gain sparse but high confidence disparity map ,the phase matching to interpolate the disparity results and the optimization theories to avoid local extrema and detect occlusion areas.The experimental results demonstrate the validity of the proposed approach..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 630 (2003)
New image correlation-matching algorithm based on edge extraction
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The accuracy and validity of the traditional image correlation-matching algorithms are degraded, with the presence of the gray change, image clutter, object variation and occlusion. The reason of degradation is that they use the method of adding the differences of the pixels' gray value according to the correspondiThe accuracy and validity of the traditional image correlation-matching algorithms are degraded, with the presence of the gray change, image clutter, object variation and occlusion. The reason of degradation is that they use the method of adding the differences of the pixels' gray value according to the corresponding position or calculating the number of the pixels having similar gray value as matching degree. A new image correlation-matching algorithm based on edge extraction is proposed. Firstly the new algorithm processes the image by extracting edge and thresholding, then calculates the correlation of the binary images using the defined ESD distance. Results show that the new algorithm is robust to more image distortions and has great value in target tracking application..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 635 (2003)
Stereoscopic color fusion and display of dual-band image
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Firstly, realization of unsynchronized dual-channel video image stereoscopic display is dissertated. Secondly, similarities and differences of dual-band image fusion and stereoscopic display are analyzed. Finally, the idea of realizing dual-band image color fusion during stereoscopic display is proposed, and dual-channFirstly, realization of unsynchronized dual-channel video image stereoscopic display is dissertated. Secondly, similarities and differences of dual-band image fusion and stereoscopic display are analyzed. Finally, the idea of realizing dual-band image color fusion during stereoscopic display is proposed, and dual-channel of ultraviolet image and low-light image color fusion in stereoscopic display is realized.
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 639 (2003)
Novel wavelet image denoising method
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Wavelet image denoising has been well acknowledged as an important method of image denoising. Recently, most of the research efforts about wavelet image denoising focus on how to select the threshold. Edge information is the most primary high frequency information of an image. Therefore maintenance of more edge informaWavelet image denoising has been well acknowledged as an important method of image denoising. Recently, most of the research efforts about wavelet image denoising focus on how to select the threshold. Edge information is the most primary high frequency information of an image. Therefore maintenance of more edge information is more important in the denoising process. According to the idea of this paper, an image denoising method based on wavelet transform and mathematic morphology is proposed. The coefficients of wavelet transform of image are manipulated by morphological operator, so as to remove the noise whose support are small area or no area at all and preserve the edge and the small features whose support are large or consecutive area. The experimental results show that, compared with the usually used wavelet threshold denoising method and median filtered method, the proposed method can keep images edges from damaging and increase PSNR to 3～5 dB and SNR to 6～10 dB respectively..
Infrared and Laser Engineering
- Publication Date: Dec. 01, 2003
- Vol. 32, Issue 6, 643 (2003)
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