共查询到20条相似文献,搜索用时 69 毫秒
1.
2.
3.
我们知道.利萨如图形的具体形状不仅决定于两个分振动的振幅比和频率比,而且与二分振动的初位相有关[1].但是我们在科研中又发现.在满足相同的振幅比、频率比和初相位一定的条件下,在同一示波器上对信号采用不同的频率范围,或者在同一频率范围内选择不同型号的示波器,也得出了不同形状的利萨如图形,这引起了我们的深思.我们在SB—10型示波器上.把同一信号分成两部分,同时送入“X输入”和“Y输入”,在改变信号频率的情况下,得到如图1所示的利萨如图形.采用同一信号,我们又在ST—16型示波器上同样得到了图2所示的利萨如图形… 相似文献
4.
具有存储功能的衍射图像光刻系统的研制 总被引:1,自引:1,他引:0
研制了一种在衍射光变图像器件上进行信息存储的新型数字化激光光刻系统。采用空间光调制器作图形自动输入,双远心投影成像系统在光刻记录面上缩微图形。通过光栅干涉光学头对记录面上的微图形进行干涉调制,使微图形上产生干涉条纹,条纹空间频率范围为500-1200lp/mm。在光刻胶干版上的存储实验表明,在衍射光变图像上的单角度存储信息密度大于3.7Mbit/cm^2。改变干涉条纹取向、条纹间隔和需要存储的图形,光刻系统可实现信息的旋转复用存储。上述光刻系统将会在防伪和衍射光变图像器件制造领域有良好应用。 相似文献
5.
利用ASP.NET语言编制了一个物理实验数据处理系统。该系统界面友好,通过最小二乘法能够自动处理输入的实验数据,拟合出曲线,分析误差,输出曲线图形,适合在实验教学中使用。 相似文献
6.
提出一种采用低空频模板实现微光变图像(micro-optical variable device)的激光直写方法。低空频模版由6×6个不同取向线条状单元图形构成,单元图形由空间光调制器输入,经精缩投影光学系统缩微,在光刻胶面上逐单元曝光。控制单元图形的结构取向能够实现各种复杂设计和特性的微光变图像。在低频光栅模板的基础上,给出了定向散斑结构输入模板的设计方法,它可进一步改进图像的非彩色效果。采用自行研制的SVG-LDW04型激光直写系统制作了微光变图像,其结构特征线度为4μm~100μm。该方法无需机械旋转机构,为实现微光变图像提供了一种便捷有效的手段。 相似文献
7.
8.
9.
用DJS-130机及部分外围设备和高速模拟量输入通道组成了一个简单的双路数据采集和处理系统。在自编软件的管理下对“微环”装置等离子体的环电流、环电压信号作了实时采集和处理,所得结果可采用数字和图形两种方式输出。 相似文献
10.
11.
12.
Huijuan Li 《Optics and Lasers in Engineering》2009,47(1):45-50
A novel optical image encryption method is proposed, based on gyrator transform and phase-shifting interferometry. The input two-dimensional image to be encrypted is gyrator transformed two times, and two random phase masks are placed at the input plane and the output plane of the first gyrator transform. Two-step phase-shifting interferometry is used to record the digital holograms of the input image encrypted by use of double-random phase encoding technique in gyrator transform domain. The rotation angles of gyrator transform, the random phase mask in the gyrator plane and the arbitrary phase shift used for recording form the keys for decryption of the input image. Numerical simulations are presented to verify its validity and efficiency. 相似文献
13.
A new method for larger size images recognition is proposed based on high-pass filtering and frequency spectrum correlation. The input images are first filtered by a high-pass filter. Then the filtered input images, which are overlapped rather than displaced from each other in the input plane, serve as the input images for frequency spectrum correlator. As a result, only one sharp correlation peak yields in the center of output plane when the target image matches with the reference image. More importantly, the method is especially suitable for larger size image recognition because of the input and correlation ways, which ensures better utilization of the space-bandwidth product and efficient utilization of the spatial light modulator and detector. Computer simulation results are presented to demonstrate the feasibility and effectiveness of this method. 相似文献
14.
15.
In this work an optical-digital correlator for pattern recognition and input scene restoration is described. Main features of the described correlator are portability and ability of multi-element input scenes processing. The correlator consists of a consumer grade digital photo camera with a diffractive optical element (DOE) inserted as a correlation filter. Correlation of an input scene with a reference image recorded on the DOE are provided optically and registered by the digital photo camera for further processing. Using obtained correlation signals and DOE’s point spread function (PSF), one can restore the image of the input scene from the image of correlation signals by digital deconvolution algorithms.The construction of the correlator based on the consumer grade digital photo camera is presented. The software procedure that is necessary for images linearization of correlation signals is described. Experimental results on optical correlation are compared with numerical simulation. The results of images restoration from conventionally and specially processed correlation signals are reported. Quantitative estimations of accuracy of correlation signals as well as restored images of the input scene are presented. 相似文献
16.
基于动态直方图均匀化的对比度增强方法 总被引:4,自引:0,他引:4
为增强显示设备进行视频信号显示时的图像对比度,提出了一种动态直方图均匀化算法,该算法根据对比度增强系数可实现在不同灰度范围内的直方图均匀化,达到不同程度的对比度增强效果。同时为减少进行对比度增强所需的帧存储器,开发出了一种快速简单的输入视频图像帧间相似性检测方法及电路实现,当判定输入视频图像具有相似性时,后续帧的图像采用前面输入图像的对比度增强映射函数。仿真结果表明,提出的对比度增强方法能根据对比度增强系数实现不同程度的对比度增强,有效地提高了显示设备的图像显示质量。 相似文献
17.
实时图像边缘增强空间光调制器 总被引:1,自引:1,他引:0
光学相关识别中首先需要一个把非相干到相干光进行转换的输入图像转换器,然后,再进入输入图像的边缘增强预处理,我们研制的光寻址单晶硅液晶光阀能够同时完成这两项功能。给出图像边缘增强的实验结果。 相似文献
18.
We present the design of correlation filters for detection of a target in a noisy input scene when the object of interest is given in a noisy reference image. The target signal, shape and location in the reference image are assumed to be unknown. Two signal models are considered for the input scene: additive and nonoverlapping. The design of the filters consists of automated estimation of needed parameters from a noisy reference image and maximization of the peak-to-output energy ratio criterion. Two filter variants are proposed. The matching error metric is used to determine the regions of the parameter space where each filter variant performs better. Computer simulation results obtained with the proposed filters are presented and evaluated in terms of discrimination capability, location errors, and tolerance to input noise. 相似文献
19.
We investigate quality of images decrypted from in-line holograms recorded with a random phase mask placed behind an input image. High- and low-contrast fingerprint images are used as test scenes. The simulation results show that due to multiple convolution processes and a limitation of the CCD sensor resolution, quality of decrypted images is sensitive to spatial separations between the input image, the phase mask and the hologram. We propose a new method for improving quality of decrypted images by using background noise removal. It is found that in comparison with high-contrast input, the low-contrast image is more robust to distortion caused by the encryption–decryption process. 相似文献
20.
In this paper two new architectures for optical image verification are proposed. Both architectures are based on conventional joint transform correlators (JTCs) adopting a Fourier hologram and can significantly improve the recovered image quality. First, an input phase-only function is Fourier transformed and then interferes with a reference wave that is diffracted from a plane wave incident on another random phase mask. Second, two phase-only functions are placed at the two input sides of a beamsplitter such that the interference pattern of their Fourier transforms can be detected. To obtain a predefined target image in the output plane, one of the input phase functions is iteratively retrieved by the use of the projection onto constraint sets algorithm. Simulation results show that the less mean squared error and better image quality are obtained for both the binary and grayscale images. 相似文献