检索结果-南通市图书馆

Cubic surface fitting to image by combination

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2010年第7期53卷 1287-1295页

作者： LI XueMei1, ZHANG CaiMing1,2, YUE YiZhen1 & WANG KunPeng1 1School of Computer Science and Technology, Shandong University, Jinan 250101, China 2School of Computer Science and Technology, Shandong Economics University, Jinan 250014, China School of Computer Science and Technology Shandong University School of Computer Science and Technology Shandong Economics University

We present a new method for constructing a fitting surface to image data. The new method is based on a supposition that the given image data are sampled from an original scene that can be represented by a surface defined by piecewise quadratic polynomials. The surface representing the original scene is known as the original surface in this paper. Unlike existing methods, which generally construct the fitting surface to the original surface using image data as interpolation data, the new method constructs the fitting surface using the image data as constraints to reverse the sampling process, which improves the approximation precision of the fitting surface. Associated with each data point and its near region, the new method constructs a quadratic polynomial patch locally using the sampling formula as constraint. The quadratic patch approximates the original surface with a quadratic polynomial precision. The fitting surface which approximates the original surface is formed by the combination of all the quadratic polynomial patches. The experiments demonstrate that compared with Bi-cubic and Separable PCC methods, the new method produced resized images with high precision and good quality.

关键词： surface fitting quadratic polynomial image resizing reversing

Applying surface fitting in the Medical Thermal Tomography Technology

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Biomedical Engineering(English Edition) 2012年第1期21卷 12-21页

作者： QIAO Yu-ting LI Kai-yang HAN Fei LI Wen-ke School of Physical Science and Technology Wuhan UniversityWuhan 430072China

Based on the thermal tomography technology, this thesis tries to calculate quantity and distribution of heat source in vivo from body surface temperature. A superposition temperature image of a number of point heat sources is surface fitted to get the Q of heat sources (information of cancer cells) quantitatively. The result can reflect the disease area information because cancer cell's Q value is much higher than that of normal cell. This application is a new try in the diagnosis of breast cancer, which has an important value on the early detection and diagnosis of disease source.

关键词： thermal tomography technology surface fitting cancer diagnosis MATLAB

Image zooming via surface fitting based on edge constraint

在线全文

学校读者我要写书评

暂无评论

Computer Aided Drafting,Design and Manufacturing 2013年第1期23卷 1-6页

作者： GUO Yingying ZHANG Caiming LI Weitao ZHOU Yuanfeng WANG Min School of Compute Science and Technology Shandong University Shandong Province Key Lab of Digital Media Technology Shandong University of Finance and Economics

In this paper we present a new image zooming algorithm based on surface fitting with edge constraint. In surface fitting,we consider not only the relationship of corresponding pixels between the original image and the enlarged image, but also the neighbor pixels in the enlarged image according to the local structure of original image. Furthermore, during surface fitting, more interpolation constraints are used in the new algorithm for improving the precision of the super sampling pixels. The experimental results show that the new method outperforms the previous methods which based on surface fitting.

关键词： image zooming surface fitting image edge

Geometric Calibration of LensUsing B-Spline surface fitting

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 1998年第4期3卷 440-442页

作者： Sun Xiao’an Chen Shuzhen Shen Qiang(College of Electronic Information. Wuhan University, Wuhan 430072, China) Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***)

A new lens calibration method which is suitable for all kinds of cameras is presented. Based on the global and local adjustable feature of B-spline surface, this method does not require the determination of distortion model of the camera lens. By applying B-spline surface fitting, all kinds of lens distortion models can be simulated. The control points of B-spline surface are estimated inversly from the feature points of detected lines. Then by moving the control points, straight line features in the image can be retrieved. Compared with traditional calibration method, this method has its unique advantage that need no corresponding points between image and scene. Experimental results show the effectiveness of the method.

关键词： calibration distortion surface fitting

Method for Improving Digital Elevation Model Precision of Consumer Level Unmanned Aerial Vehicles

在线全文

学校读者我要写书评

暂无评论

Meteorological and Environmental Research 2024年第2期15卷 71-77页

作者： Qiuxin XIA Zhong LI Yong ZHOU Ensi ZHANG Gang YANG Nanjing Les Information Technology Co. Ltd.Nanjing 210001China

Currently,the aerial survey system of low-altitude unmanned aerial vehicles(UAVs)has been widely used in acquiring digital map 4D products,mapping,digital linear maps,and other ***,there are problems,such as low precision and weak practicability in constructing digital elevation model(DEM)products through the data collected using consumption level ***,improving the accuracy of DEM products obtained by consumption level UAVs is a crucial and complex issue in the research of UAV aerial survey *** precision elevation measurement,the geodetic height of a certain number of ground points with reasonable distribution in the region is often obtained ***,the normal height of the ground points is obtained by leveling,and the elevation residual value surface of the region is ***,the normal height of the points to be solved in the region is obtained by fitting the elevation residual ***,the elevation residual fitting method was used to improve the accuracy of consumer UAV DEM products in this ***,a high-quality ground point cloud was obtained by constructing the gradient filtering-cloth simulation filtering(GF-CSF)***,an abnormal elevation fitting residual DEM model was ***,the final DEM was obtained using the DEM difference *** experimental results show that among the 20 random sampling inspection points,the average elevation residual was 2.3 mm,and the root mean square error(RMSE)was 16.7 mm after the DEM accuracy was improved by the *** average elevation residual without improving the DEM accuracy was 28.6 mm,and RMSE was 33.7 mm.

关键词： UAV aerial survey GF CSF DEM surface fitting

Lumiproxy:A Hybrid Representation of Image-Based Models

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2009年第3期24卷 578-587页

作者：盛斌朱鉴吴恩华张言辞 Department of Computer Science and Engineering The Chinese University of Hong Kong Faculty of Science and Technology University of Macao Institute of Software Chinese Academy of Sciences Department of Informatics University of Zurich

In this paper, we present a hybrid representation of image-based models combining the textured planes and the hierarchical points. Taking a set of depth images as input, our method starts from classifying input pixels into two categories, indicating the planar and non-planar surfaces respectively. For the planar surfaces, the geometric coefficients are reconstructed to form the uniformly sampled textures. For nearly planar surfaces, some textured planes, called lumiproxies, are constructed to represent the equivalent visual appearance. The Hough transform is used to find the positions of these textured planes, and optic flow measures are used to determine their textures. For remaining pixels corresponding to the non-planar geometries, the point primitive is applied, reorganized as the OBB-tree structure. Then, texture mapping and point splatting are employed together to render the novel views, with the hardware acceleration.

关键词： lumiproxy sampling surface fitting image-based rendering

A High Precision Software Compensation Algorithm for Silicon Piezoresistive Pressure Sensor

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2019年第4期28卷 748-753页

作者： WU Tianshu CHEN Shuyu WU Peng NIE Shaozhong College of Computer Science Chongqing University Chongqing Chuanyi Automation Co. Ltd.

There are generally zero drift, sensitivity drift and nonlinear error in silicon piezoresistive pressure sensors due to the inherent characteristics of semiconductor materials. It is necessary to compensate and correct the errors produced so as to meet the requirements of measurement accuracy. In order to further improve the compensation precision, based on the research of various basic software compensation methods, a surface fitting compensation algorithm based on least square method is designed, and the software is implemented on the Visual Basic platform. The experimental results show that the zero drift, sensitivity drift and nonlinear error is effectively eliminated, and the output precision of the sensor is greatly improved.

关键词： High precision compensation algorithm Least square method surface fitting

Global Continuity Adjustment and Local Shape Optimization Technique for Complex Trimmed surface Model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2010年第2期23卷 225-232页

作者： BIAN Keke KE Yinglin The State Key Lab of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

Smoothly stitching multiple surfaces mainly represented by B-spline or NURBS together is an extremely important issue in complex surfaces modeling and reverse engineering. In recent years, a lot of progress has been made in smooth join of non-trimmed surface patches, while there has been seldom research on smoothly stitching trimmed surface patches together. This paper studies the problem of global continuity adjustment, damaged hole repair and local shape optimization for complex trimmed surface model, and presents a uniform scheme to deal with continuity adjustment of trimmed surfaces and geometric repair of local broken region. Constrained B-spline surface refitting technique and trim calculation are first utilized to achieve global G^1 continuity, and then local shape optimization functional is adopted to reduce fitting error and improve local quality of refitted surface patch. The proposed approach is applied to a discontinuity ship hull surface model with an irregular hole, and the result demonstrates the validation of our method. Furthermore, on the premise of global continuity, the proposed locally repairing damaged surface model provides a better foundation for following research work, such as topology recovery technique for complex surface model after geometric repair.

关键词： computer aided geometric design(CAGD) geometric continuity trimmed surface surface fitting shape optimization reverse engineering

fitting C1 surfaceS TO SCATTERED DATA WITH S 1 2 （△ m,n （2））

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2011年第4期29卷 396-414页

作者： Kai Qu Renhong Wang Chungang Zhu School of Mathematical Sciences Dalian University of Technology Dalian 116024 China Department of Mathematics Dalian Maritime University Dalian 116026 China

This paper presents a fast algorithm （BS2 Algorithm） for fitting C 1 surfaces to scat- tered data points. By using energy minimization, the bivariate spline space S 2 1（△ m,n （2）） is introduced to construct a Cl-continuous piecewise quadratic surface through a set of irregularly 3D points. Moreover, a multilevel method is also presented. Some experimental results show that the accuracy is satisfactory. Furthermore, the BS2 Algorithm is more suitable for fitting surfaces if the given data points have some measurement errors.

关键词： Bivariate spline Scattered data surface fitting Energy minimization Type-2triangulation C1-continuous.