扫描输入平面的强度相关器

对强度相关器中输入平面轴向位移实现尺度变化相关进行了理论分析。给出了尺度因子可允许变化范围的理论公式并进行了估算。     

基于旋转和尺度不变性的图像识别研究

根据对数极坐标转换的尺度与旋转不变性特征,进行了角度发生变化、尺度发生变化和角度与尺度同时发生变化情况下的相似度分析.研究了转换阵识别的一维统计匹配、二维转换阵匹配、双边缘信息匹配三种算法并且进行了相关实验及实验结果的数据分析.     

激光扫描声学显微镜中透镜效应的研究

通过对激光扫描声学显微镜（ＳＬＡＭ）光学成像系统的研究,推导了ＳＬＡＭ中透镜组的相关传递函数,计算了秀镜对ＳＬＡＭ图像的空间截止频率,提出了消除透镜效应的数值计算方法,并应用了ＳＬＡＭ图像的处理中,取得了较好的效果。     

目标尺度、旋转变化对相关峰质量的影响

为了描述目标图像尺度、旋转变化对相关峰质量的影响,选取并定义了峰噪比、相关峰值能量、Horner效率、半峰宽度和最高峰值强度这五个特征参数;运用Matlab软件详细分析了五个特征参数对尺度、旋转变化的响应;通过分析得出原始图像尺度、旋转变化对相关峰质量影响的一般规律;分析了五个特征参数的适用范围、效果以及局限性,为改善相关峰质量提供了参考.     

消除相干噪声的偏心旋转透镜法

本文介绍了一种简单适用,照度均匀,光场大小可调而又很少损失光能的消除相干噪声的技术。     

录像机中相关器的作用

近来录像机中处理复合视频信号时多用相关型梳状滤波器，叙述相关器作用原理，理想的解决了亮／色分离问题。     

基于强度调制和布里渊效应的六倍频可调毫米波信号产生

提出了一种新型的基于马赫-曾德尔调制器(MZM)和布里渊效应实现六倍频可调毫米波信号输出的方法。在本方案中,先调节MZM的直流偏置,抑制偶数边带,留下奇数边带;经过大功率掺Er3+光纤放大器(EDFA)放大之后,使两个一阶边带的功率达到布里渊阈值之上,然后采用了25km的单模光纤(SMF)作为布里渊介质,滤除一阶边带,留下三阶边带;最后经过EDFA放大和光电探测器(PD)光电转换得到六倍频的毫米波信号。因为布里渊边带滤波是窄带滤波,与波长无关,故本系统可以实现波长无关的微波信号产生。     

Matched wavelet filtering of signals with change scale

A new matched filtering method with the use of normalization “in terms of level”, when the scale of signals is different, is suggested.     

Electronic erasure of stored reference signals in a metal-ZnO-SiO2-Si induced junction storage correlator

The surface-acoustic-wave storage correlator is used to store a reference signal for subsequent correlation with an unknown signal. We describe and demonstrate a method for the electronic erasure of stored signals in the context of the MZOS-induced junction storage correlator.     

Magnetostatic correlator of microwave signals with the internal wave front reversal

A new technique of the correlation processing of data based on the nonlinear interaction of signals of backward volume magnetostatic waves in yttrium-iron garnet thin films and a corresponding laboratory mock-up of the correlation receiver operating in the 6 cm wavelength range have been presented in this paper. It was proposed to use additional pumping pulse for obtaining a time-reversed signal pulse. The resultant correlation signal occurred during the nonlinear interaction of the delayed signal wave and the pumping-reversed wave. The specificity of the passage of broadband signals through the resonance system of waveguide of spin waves was taken into account. It has been found out that the resonance properties of the correlator affect the efficiency of the desired signal separation from the noise level. The resultant signal-to-noise ratio for the output signal was enhanced by more than 20 dB.     

Design and characterization of a real-time correlator

The design and characterization of a real-time correlator/electrically programmable transversal filter is presented, based on a novel functional multiplying structure in a standard single-level MOS LSI process. The analog information is sampled and held at fixed sites on the chip and the tap weights slide past them; the taps are digitized into 7 bits which control the selection of seven binary area-ratioed MOS capacitors per tap position. The rotation of the tap weights can reduce the effect of tap-weight errors but contributes to fixed pattern noise. Experiments using cascaded chips to build longer filters show excellent transfer-function agreement with theory. Dynamic range of the device is limited primarily by fixed pattern noise. This problem has been modeled and at present about a 45-dB dynamic range has been obtained for the heaviest doped chips when driven by input-signal amplitudes which allow better than 1-percent harmonic distortion. With improvements suggested, significant increases are expected in the dynamic range of the device.     

Translation, rotation and scale stabilisation of image sequences

Translation, rotation and scale stabilisation of image sequences is presented with phase correlation based estimation of motion parameters. Phase correlation and log-polar magnitude spectra representation is utilised to obtain translation, rotation and scale parameters. Stabilised frame positions are obtained through Kalman filtering of absolute parameters, and image frames are processed accordingly so as to result in a sequence that displays smooth global movements only.     

Noninvasive measurement of physiological signals on a modified home bathroom scale

A commercial bathroom scale with both handlebar and footpad electrodes was modified to enable measurement of four physiological signals: the ballistocardiogram (BCG), electrocardiogram (ECG), lower body impedance plethysmogram (IPG), and lower body electromyogram (EMG). The BCG, which describes the reaction of the body to cardiac ejection of blood, was measured using the strain gauges in the scale. The ECG was detected using handlebar electrodes with a two-electrode amplifier. For the lower body IPG, the two electrodes under the subject's toes were driven with an ac current stimulus, and the resulting differential voltage across the heels was measured and demodulated synchronously with the source. The voltage signal from the same two footpad electrodes under the heels was passed through a passive low-pass filter network into another amplifier, and the output was the lower body EMG signal. The signals were measured from nine healthy subjects, and the average signal-to-noise ratio (SNR) while the subjects were standing still was estimated for the four signals as follows: BCG, 7.6 dB; ECG, 15.8 dB; IPG, 10.7 dB. During periods of motion, the decrease in SNR for the BCG signal was found to be correlated to the increase in rms power for the lower body EMG (r = 0.89, p <; 0.01). The EMG could, thus, be used to flag noise-corrupted segments of the BCG, increasing the measurement robustness. This setup could be used for monitoring the cardiovascular health of patients at home.     

Improving the performance of a low-frequency correlator

A technique for improving the performance of a low-frequency correlator whose design is centred on a bucket-brigade delay line is presented. The technique is based on a concept which uses the unprocessed output of the delay line.     

Phase and amplitude storage of an acoustic signal in a Schottky-diode correlator

An experiment is described wherein a matrix of Schottky diodes, biased by a short voltage pulse, stores an s.a.w. signal and then delivers its correlation with a signal arriving later. Phase and amplitude storage are demonstrated.     

使用M进制小波对尺度与旋转不变的图像特征点进行检测

基于小波变换和尺度空间理论,提出了一种尺度与旋转不变的图像特征点的检测方法。首先对图像进行多尺度的M进制小波变换,然后根据M进制小波变换系数的能量构造对应的二阶矩阵,最后通过考察该矩阵的特征值确定图像的特征点。实验表明,与目前最常用的方法相比,本文方法对图像的旋转变化与尺度变化均具有更好的不变性,在光照变化和噪声干扰等外部条件影响下也能保持较高的鲁棒性。