共查询到17条相似文献,搜索用时 93 毫秒
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基于光学子波变换的SDF匹配滤波器 总被引:2,自引:1,他引:2
提出了一种基于光学子波变换的综合判别函数匹配滤波器(WFSDF),将光学子波变换和综合判别函数相结合,只用一个简单的4f系统就能实现输入图像和SDF子波变换的相关运算。采用计算全息的方法制作复数匹配滤波器。计算机模拟仿真结果表明,与传统的SDF匹配滤波器相比,WFSDF匹配滤波器,锐化了相关峰,提高了识别率,同时简化了光路,能够实现多目标的畸不变识别。 相似文献
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应用计算全息制作的子波匹配滤波器实现光学子波变换的研究 总被引:6,自引:0,他引:6
介绍了一种应用计算全息制作的子波匹配滤波器实现光学子波变换的新方法,应用计算全息制作Haar子波函数的匹配滤波器和光学Vander Lugt相关器实现了二维子波变换,给出了实验结果。这种方法可实现任意子波函数的光学子波变换,且简单易行。 相似文献
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共光轴体全息存储是体全息存储技术实用化的一个发展方向。为了选择合适的参数以搭建基于晶体的透射式共光轴体全息存储系统,对该系统的存储容量、串扰特性和晶体在共光轴存储结构中的存储特性等进行了研究。从理论上分析了共光轴体全息存储系统的存储密度、物镜的参数、空间光调制器的像素尺寸、有效像素数目和移位复用间隔等之间的关系,给出了点扩展函数表达式的物理解释,并根据点扩展函数分析了系统的串扰特性,优化了存储偏振光方向以使晶体表现出最大的动态范围。根据分析优化结果搭建了基于LiNbO3晶体的透射式共光轴体全息存储实验系统,实现了高分辨图像的记录与再现。与传统的双轴系统相比,所搭建的共光轴系统具有光路结构紧凑的特点。 相似文献
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《中国光学与应用光学文摘》2007,(3)
光学滤波与频谱分析O438.22007032391基于光学子波变换的SDF匹配滤波器=SDF matching fil-ter based on optical wavelet transform[刊,中]/张琳丽(西安建筑科技大学理学院物理系.陕西,西安(710055)),盛利//光学技术.?2007,33(1).?156-158提出了一种基于光学子波变换的综合判别函数匹配滤波器(WFSDF),将光学子波变换和综合判别函数相结合,只用一个简单的4f系统就能实现输入图像和SDF子波变换的相关运算。采用计算全息的方法制作复数匹配滤波器。计算机模拟仿真结果表明,与传统的SDF匹配滤波器相比,WFSDF匹配滤波器,锐化了相关峰,… 相似文献
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本文针对层状多重体全息在红外通讯波段分光滤波的应用,分析了其布喇格匹配与衍射效率均匀性问题.给出了在LiNbO3∶Fe光折变晶体中制作层状多重体全息光栅的几种方法.利用双片光干涉在直接分层结构中写入了三层光栅,光栅层厚1 mm,层间距2 mm,每层复用了四个光栅.对这三层光栅的分析测试表明,12个光栅的衍射效率均匀,相邻通道间隔约3 nm.实验结果表明,这种层状结构的多重体全息光栅有希望用来组成具有大量通道数的WDM系统中的复用/解复用器件. 相似文献
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菌紫质是一种结构和功能与高级动物视网的视生色素--视紫红质极为相似的蛋白南,是一种优异的可逆光全息记录材料,子波变换是目标特征抽取和模式识别和有效方法。本文钭联合子波变换和菌紫质膜优异的光学全息记录特性结合起来,提出了一种全新的光学全息实时模式识别方案,给出了相应的实验结果。 相似文献
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增强现实抬头显示(AR-HUD)是下一代智能座舱的关键显示系统,能够极大地提升驾驶安全性和体验感。基于体全息光波导的AR-HUD具有光学系统体积小、能量利用率高等优势,是AR-HUD领域关注的重点。然而,传统基于棱镜耦合的双光束曝光方法实现大幅面体全息光波导的制造极具挑战性。从体全息光波导的曝光参数出发,在矢量球中基于光栅简并理论给出了非全反射条件下体全息光波导曝光的参数设计方法,设计并搭建了一套大幅面体全息光波导自动化拼接曝光系统,制作了幅面尺寸为130 mm×270 mm的大幅面体全息光波导,并给出了增强现实显示效果。 相似文献
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The wavelet and harmonic filtering method suggested by Zalevsky and Ouzieli is introduced in this paper and adopted in our volume holographic image recognition system. This composite filter combines several scaled versions of the cascaded wavelet and harmonic filter, obtaining high discrimination ability and wide dynamic range of rotation and scale deformations. Optical experiments are conducted to demonstrate the validity and practicability of the algorithm. To the best of our knowledge, this is the first report of using this algorithm in a volume holographic system. Moreover, the separate correlation approach proposed in this paper greatly simplifies the manufacturing process and reduces the cost of the system. 相似文献
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A volume holographic wavelet correlation processor for performing rotation invariant Pattern recognitionis suggested.It uses wavelet transform to get the digital edge extraction of the original object and a singlecircular harmonic component iS used as the matched filter to get good rotation invariance.The new filterused in this method is called wavelet circular harmonic component fllter (WCHCF).Simulation resultsvalidate the theory and the experiment to recognize human faces with any rotation angle shows the utilityof the newly proposed method. 相似文献
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基于数字全息与小波变换的图像数字水印技术 总被引:2,自引:0,他引:2
提出一种以数字全息和小波变换为基础的数字水印技术,实现在原始图像中嵌入数字全息水印。首先通过傅里叶变换方法将待隐藏的图像制成数字全息水印图,接着将数字全息水印图和原始图像都分为四个子块,并对原始图像子块进行小波分解,最后将数字全息图像子块嵌入到原始图像相应子块较大的小波系数中。实验仿真结果证明了该水印技术对图像剪切和图像有损压缩有较好的稳定性。 相似文献
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Principles of the photorefractive perceptron learning algorithm are described. The influences of the finite response time and hologram erasure of the photorefractive gratings on the convergence property of the photorefractive perceptron learning are discussed. A novel neural network which could resolve these constraints is presented. It is a hybrid system which utilizes the photorefractive holographic gratings to implement the inner product between the input image and the interconnection matrix. A personal computer is used for storing the interconnection matrix and the updating procedure, and it also functions as a feedback means during the learning phase. After training the weight vectors are recorded in the volume hologram of an optical processor. This novel method combines the advantages of the massive parallelism of optical systems and the programmability of electronic computers. Experimental results of image classification are presented. It shows that the system could correctly classify the input patterns into one of the two groups after training on four examples in each group during successive iterations. The system has been extended to perform multi-category image classification. 相似文献
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Sidelobe suppression in volume holographic optical correlators by use of speckle modulation 总被引:1,自引:0,他引:1
By use of speckle modulation on the object beam of a volume holographic optical correlation system, we show that the sidelobes of the correlation patterns along the vertical direction, as well as those along the horizontal direction, are well suppressed. A theoretical explanation and experimental results are presented and discussed. 相似文献