共查询到20条相似文献，搜索用时 31 毫秒
1.
对一阶形函数进行分析,发现其不匹配所造成误差与同样窗口大小的均值滤波有着紧密的联系。探索一次和二次均值滤波对数据的平滑效应,发现多次滤波所造成的数据差之间存在一定的可类比性,因此将两次均值滤波形成的数据差作为一次均值滤波数据差的估计,以此为基础对原数据进行恢复,用来抑制由于形函数不匹配所造成的误差。分别将本方法应用到简单正弦函数和混合函数,以及另外模拟了数字散斑图像,并进行了数字图像相关运算,以本方法对位移数据进行恢复,取得了良好的效果。实验结果表明,本方法能够有效抑制由于形函数不匹配所造成的位移测量误差,有助于进一步提高数字图像相关技术对于非均匀变形的测量精度。 相似文献
2.
针对数字图像版权保护的问题,设计了一种基于离散小波变换和图像分存的数字水印算法。算法将水印信息随机嵌入到图像的小波分解中频系数中,并且使用纠错编码和置乱加密,以增强算法的安全性。实验结果表明该算法是有效的。 相似文献
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Statistical and contextual information are typically used to detect moving regions in image sequences for a fixed camera. In this paper, we propose a fast and stable linear discriminant approach based on Gaussian Single Model （GSM） and Markov Random Field （MRF）, The performance of GSM is analyzed first, and then two main improvements corresponding to the drawbacks of GSM are proposed： the latest filtered data based update scheme of the background model and the linear classification judgment rule based on spatial-temporal feature specified by MRF. Experimental results show that the proposed method runs more rapidly and accurately when compared with other methods. 相似文献
4.
In order to sufficiently exploit the advantages of different signal processing methods, such as wavelet transformation (WT), artificial neural networks (ANN) and expert rules (ER), a synthesized multi-method was introduced to detect and classify the epileptic waves in the EEG data. Using this method, at first, the epileptic waves were detected from pre-processed EEG data at different scales by WT, then the characteristic parameters of the chosen candidates of epileptic waves were extracted and sent into the well-trained ANN to identify and classify the true epileptic waves,and at last, the detected epileptic waves were certificated by ER. The statistic results of detection and classification show that, the synthesized multi-method has a good capacity to extract signal features and to shield the signals from the random noise. This method is especially fit for the analysis of the biomedical signals in biomedical engineering which are usually non-placid and nonlinear. 相似文献
5.
图像去噪是图像分割等操作的关键预处理环节,是从图像处理过度到图像分析和理解的重要手段之一,是图像处理中研究的重点内容.现有典型的一些图像去噪方法大多采用平滑滤波机理,在保护图像边缘信息等方面存在一定的局限性. 本文在对现有典型的图像去噪方法总结的基础上,提出了一种图像去噪的新方法--利用支持向量机(SVM)技术构建图像去噪滤波器,并在实现算法和实验仿真方面做了初步探讨. 相似文献
6.
Automatic segmentation of bladder in CT images 总被引：1，自引：0，他引：1
Segmentation of the bladder in computerized tomography （CT） images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First, we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder, which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity, specificity, positive predictive value, negative predictive value, and Hausdorffdistance are 86.5%, 96.3%, 90.5%, 96.5%, and 2.8 pixels, respectively. The results show that the bladder can be accurately segmented. 相似文献
7.
Power Quality （PQ） combined disturbances become common along with ubiquity of voltage flickers and harmonics. This paper presents a novel approach to classify the different patterns of PQ combined disturbances. The classification system consists of two parts, namely the feature extraction and the automatic recognition. In the feature extraction stage, Phase Space Reconstruction （PSR）, a time series analysis tool, is utilized to construct disturbance signal trajectories. For these trajectories, several indices are proposed to form the feature vectors. Support Vector Machines （SVMs） are then implemented to recognize the different patterns and to evaluate the efficiencies. The types of disturbances discussed include a combination of short-term disturbances （voltage sags, swells） and long-term disturbances （flickers, harmonics）, as well as their homologous single ones. The feasibilities of the proposed approach are verified by simulation with thousands of PQ events. Comparison studies based on Wavelet Transform （WT） and Artificial Neural Network （ANN） are also reported to show its advantages. 相似文献
8.
The expression of residual is obtained according to its dynamic response to mean shift,then the distribution of T 2 statistic applied to the residual is derived,thus the probability of the T 2 statistic lying outside the control limit is calculated.The above-mentioned results are substituted into the infinite definition expression of the average run length(ARL),and then the final finite ARL expression is obtained.An example is used to demonstrate the procedures of the proposed method.In the comparative study,eight autocorrelated processes and four different mean shifts are performed,and the ARL values of the proposed method are compared with those obtained by simulation method with 50,000 replications.The accuracy of the proposed method can be illustrated through the comparative results. 相似文献
9.
移动通信中的多谱勒频偏估计方法 总被引：1，自引：0，他引：1
针对几种多普勒频偏估计方法,分别为对数包络法、自相关函数法、各阶电平通过率法和均方相位差分法,在理论上分析了瑞利信道中它们的估计原理和估计偏差,说明了这些估计方法各自的适用场合.同时推导了多普勒频偏估计器的CRB (Cramer Rao bound),并且提出了一种新的利用二阶多项式拟合的修正方法以提高多普勒频偏估计精度.算法验证采用门特卡罗计算机仿真,结果表明,相对于原始估计方法,拟合修正后的方法估计性能得到了较大的提高. 相似文献
10.
Kok-Sing Tang 《International Journal of Science Education》2016,38(13):2069-2095
The purpose of this study is to examines the relationship between the communicative approach of classroom talk and the modes of representations used by science teachers. Based on video data from two physics classrooms in Singapore, a recurring pattern in the relationship was observed as the teaching sequence of a lesson unfolded. It was found that as the mode of representation shifted from enactive (action based) to iconic (image based) to symbolic (language based), there was a concurrent and coordinated shift in the classroom communicative approach from interactive–dialogic to interactive–authoritative to non-interactive–authoritative. Specifically, the shift from enactive to iconic to symbolic representations occurred mainly within the interactive–dialogic approach while the shift towards the interactive–authoritative and non-interactive–authoritative approaches occurred when symbolic modes of representation were used. This concurrent and coordinated shift has implications on how we conceive the use of representations in conjunction with the co-occurring classroom discourse, both theoretically and pedagogically. 相似文献
11.
Design of ERT system 总被引：2，自引：0，他引：2
INTRODUCTION Electrical resistance tomography (ERT) is a technique producing images based upon variations in conductivity, and has great potential in process ap- plications (Tapp et al., 2003). In an ERT system, current is injected to a pair of drive electrodes and voltage measurements are taken between sense elec- trode pairs, yielding resistance information for image reconstruction (Cilliers et al., 2001). Traditional ERT systems usually use high fre- quency sinusoidal waveforms as … 相似文献
12.
王斌 《孝感职业技术学院学报》2006,9(4):90-92
GDI 是通过调用COM组件来实现图像文件的访问.使用GDI 实现位图到JPEG格式的转换首先在注册表中查找具体格式图像的编码方式,然后建立图形对象,最后调用COM组件完成BMP图像文件的装载与JPEG图像文件的保存. 相似文献
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INTRODUCTION Networked Control System (NCS) is composed of a central controller and a remote system containing a physical plant, sensors and actuators (Halevi and Ray, 1988; Nilsson, 1998; Walsh et al., 1999a; 1999b; Branicky et al., 2000). The controller and the plant are located at different spatial locations and directly connected through network to form a closed loop control. Fig.1 shows the NCS configuration and the time delay induced by network, where u is the control signal an… 相似文献
14.
EcoWellness: integrating the natural world into wilderness therapy settings with intentionality 总被引：1，自引：0，他引：1
Ryan F. Reese Sabrina Hadeed Hannah Craig Alia Beyer Marjorie Gosling 《Journal of Adventure Education & Outdoor Learning》2019,19(3):202-215
Wilderness Therapy (WT) programming has been criticized for underutilizing nature as an active co-facilitator in treatment. Although some concept models in the field take into account nature’s contributions in WT, an abundance of multidisciplinary research suggests that nature contact and connection could be of greater emphasis. The purpose of this article is to introduce the EcoWellness model as one empirically based approach for facilitating intentional nature connection in WT. The state of WT research and supporting theory are reported. The EcoWellness framework is overviewed and embedded within the multidisciplinary literature. A case example is presented and implications for integrating EcoWellness into WT practice, training, and research are discussed. 相似文献
15.
Trevor Cooling 《British Journal of Religious Education》2020,42(4):403-414
ABSTRACT The notion of worldview figures prominently in the recent discourse surrounding Religious Education (RE) in English schools following the publication of the final report of the Commission on Religious Education (CoRE) in 2018. This article reflects on the veracity of this initiative. It begins with an autobiographical reflection on the impact of worldview on the author’s development as a scholar. Then, the work of several critics of CoRE is discussed and a more nuanced understanding of worldview is developed as a result. Finally, the pedagogical implications of the shift to worldview are explored by drawing on the personal development approach of Michael Grimmitt and the responsible hermeneutics approach of Anthony Thiselton. 相似文献
16.
In this paper we propse a semi-fragile watermarking scheme,which can be used for image authentication.Let the original image be performed by l-level discrete wavelet transformation.An approximate wavelet coefficient matrix of the original image and real-value chaotic sequences are than used to generate the content-based and secure watermark.The watermark is embedded into original image by using by using HVS.The tamper detection can idantify the tampered region of the received watermarked image,Experimental results are given. 相似文献
17.
选用瑞利分布模型对SAR图像进行恒虚警率(CFAR)检测。提出新的参考窗口选取方法,并针对虚警特点提出新的均值估计方法。实验证明,与一般的均值估计方法相比,文中提出的均值估计方法是可行的、有效的,且与其中提出的参考窗口选取方法相结合能更好地去除虚警,保留目标信息。 相似文献
18.
涂传滨 《福建师大福清分校学报》2001,(2):21-24
分布式多层应用是传统的客户／服务器模式的替代品，微软的ＣＯＭ／ＤＣＯＭ／ＣＯＭ＋是其核心技术。本文论述了 Ｄｅｌｐｈｉ ５．０在此方面的一些关键技术指标和用Ｄｅｌｐｈｉ５．０开发分布式多层应用系统的一般步骤。最后给出了一个实例的代码片 段 相似文献
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WU Xue-dong SONG Zhi-huan 《浙江大学学报(A卷英文版)》2007,8(10):1604-1613
Determination of relative three-dimensional (3D) position, orientation, and relative motion between two reference frames is an important problem in robotic guidance, manipulation, and assembly as well as in other fields such as photogrammetry. A solution to pose and motion estimation problem that uses two-dimensional (2D) intensity images from a single camera is de- sirable for real-time applications. The difficulty in performing this measurement is that the process of projecting 3D object features to 2D images is a nonlinear transformation. In this paper, the 3D transformation is modeled as a nonlinear stochastic system with the state estimation providing six degrees-of-freedom motion and position values, using line features in image plane as measuring inputs and dual quaternion to represent both rotation and translation in a unified notation. A filtering method called the Gaussian particle filter (GPF) based on the particle filtering concept is presented for 3D pose and motion estimation of a moving target from monocular image sequences. The method has been implemented with simulated data, and simulation results are provided along with comparisons to the extended Kalman filter (EKF) and the unscented Kalman filter (UKF) to show the relative advantages of the GPF. Simulation results showed that GPF is a superior alternative to EKF and UKF. 相似文献