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Speckle intensity images of target based on Monte Carlo method
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作者 武颖丽 吴振森 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期545-549,共5页
Speckle intensity in the detector plane is deduced in the free-space optical system and imaging system based on Van Cittert-Zemike theorem. The speckle intensity images of plane target and conical target are obtained ... Speckle intensity in the detector plane is deduced in the free-space optical system and imaging system based on Van Cittert-Zemike theorem. The speckle intensity images of plane target and conical target are obtained by using the Monte Carlo method and measured experimentally. The results show that when the range extent of target is smaller, the speckle size along the same direction become longer, and the speckle size increase with increasing incident light wavelengths. The speckle size increases and the speckle intensity images of target is closer to the actual object when the aperture scale augments. These findings are useful to access the target information by speckle in laser radar systems. 展开更多
关键词 laser scattering Monte Carlo method SPECKLE intensity images
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REDUCING RF EXCITE PULSE INTENSITY TO IMPROVE MRI IMAGE QUALITY IN SOME OF COILS
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《Chinese Journal of Biomedical Engineering(English Edition)》 1999年第4期89-90,共2页
关键词 MRI RF REDUCING RF EXCITE PULSE intensity TO IMPROVE MRI IMAGE QUALITY IN SOME OF COILS
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A survey of occlusion detection method for visual object
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作者 张世辉 He Huan +3 位作者 Liu Jianxin Zhang Yucheng Pang Yunchong Sang Yu 《High Technology Letters》 EI CAS 2016年第3期256-265,共10页
Occlusion problem is one of the challenging issues in vision field for a long time,and the occlusion phenomenon of visual object will be involved in many vision research fields. Once the occlusion occurs in a visual s... Occlusion problem is one of the challenging issues in vision field for a long time,and the occlusion phenomenon of visual object will be involved in many vision research fields. Once the occlusion occurs in a visual system,it will affect the effects of object recognition,tracking,observation and operation,so detecting occlusion autonomously should be one of the abilities for an intelligent vision system. The research on occlusion detection method for visual object has increasingly attracted attentions of scholars. First,the definition and classification of the occlusion problem are presented.Then,the characteristics and deficiencies of the occlusion detection methods based on the intensity image and the depth image are analyzed respectively,and the existing occlusion detection methods are compared. Finally,the problems of existing occlusion detection methods and possible research directions are pointed out. 展开更多
关键词 visual object occlusion detection intensity image depth image
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Minimizing the effects of unmodulated light and uneven intensity profile on the holographic images reconstructed by pixelated spatial light modulators
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作者 Jhen-Si Chen Jia Jia and Daping Chu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2017年第10期42-45,共4页
A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform im... A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform image is produced by purposely shifting the holographic images of multiple reconstructed lights with different incident angles from the zero-diffraction-order and overlapping those selected different orders. The simulation and optical experimental results show that the influence of the zero-diffraction-order can be reduced, while keeping the good uniformity of the target images by this new approach. 展开更多
关键词 Minimizing the effects of unmodulated light and uneven intensity profile on the holographic images reconstructed by pixelated spatial light modulators
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Novel Model Using Kernel Function and Local Intensity Information for Noise Image Segmentation 被引量:2
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作者 Gang Li Haifang Li Ling Zhang 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2018年第3期303-314,共12页
It remains a challenging task to segment images that are distorted by noise and intensity inhomogeneity.To overcome these problems, in this paper, we present a novel region-based active contour model based on local in... It remains a challenging task to segment images that are distorted by noise and intensity inhomogeneity.To overcome these problems, in this paper, we present a novel region-based active contour model based on local intensity information and a kernel metric. By introducing intensity information about the local region, the proposed model can accurately segment images with intensity inhomogeneity. To enhance the model's robustness to noise and outliers, we introduce a kernel metric as its objective functional. To more accurately detect boundaries, we apply convex optimization to this new model, which uses a weighted total-variation norm given by an edge indicator function. Lastly, we use the split Bregman iteration method to obtain the numerical solution. We conducted an extensive series of experiments on both synthetic and real images to evaluate our proposed method, and the results demonstrate significant improvements in terms of efficiency and accuracy, compared with the performance of currently popular methods. 展开更多
关键词 kernel metric image segmentation local intensity information convex optimization
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Effects of light intensity on reflective ghost imaging 被引量:1
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作者 段徳洋 杜少将 +4 位作者 闫丽 姜盛山 刘元元 张路 夏云杰 《Chinese Optics Letters》 SCIE EI CAS CSCD 2014年第7期63-66,共4页
In this letter, we analyze the effects of light intensity find that the brightness of reflective ghost image can on reflective ghost imaging with thermal source. We be changed by modulating the light intensity of the ... In this letter, we analyze the effects of light intensity find that the brightness of reflective ghost image can on reflective ghost imaging with thermal source. We be changed by modulating the light intensity of the source and the splitting ratio of the beam splitter. The signal-to-noise ratio will be improved by increa.sing the light intensity of the source. More important, we can obtain the reflective ghost image with high image quality by adopting a low light intensity signal beam and a high light intensity reference beam, which is better than the classical optical imaging, because it can reduce the effects of light on the object. 展开更多
关键词 Effects of light intensity on reflective ghost imaging
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