Query: 3D surface parameter fitting based on MATLAB

title: Application of interpolation finite element methods to a real 3D leaf data
abstract: In this paper we proposed a new surface fitting method based on combining the Clough Tocher method (CT) and multiquadric radial basis function enhanced with a cubic polynomial (MRBFC) method to accurately reconstruct a real leaf surface from 3D scattered data. The accuracy of the CT MRBFC method is validated by implementing it to a real 3D leaf data. The accuracy of the method depends highly on the RBF shape parameter and the triangular mesh structure. Consequently we employed three different methods numerically to estimate the RBF parameter as variable or constant including the square root method, the cubic root method and the fminbnd method which is a MATLAB command based on minimizing a single variable function locally on a fixed interval. Moreover, the quality of the triangles in the mesh is measured to ensure that each triangle is close to equilateral triangle to achieve a better accuracy of the proposed CT MRBFC method. It is concluded that the proposed CT RBFC method generates an accurate representation of the leaf surface.

title: The 3D Human Body Modeling for Virtual Fitting Based on the Key Characteristic Parameters
abstract: With the development of Internet and e commerce in recent years, it has become an urgent need for e commerce users to buy satisfactory clothes through virtual fitting. Therefore, it is of great significance to research and develop a virtual fitting system that can help users create 3D human models to express their personality quickly and effectively by simply entering key characteristic parameters. By using computer simulation and 3D modeling technology, we focus on analyzing and selecting key parts and characteristic parameters that affect the effect of dressing, and study how to create the contour of human body's key parts by leveraging these key characteristic parameters. And then, the contour is used to create 3D human surface model, based on which personalized 3D human body model for virtual fitting can be quickly and effectively created through users' modification of key characteristic parameters.

title: 3D surface reconstruction of small height object based on thin structured light scanning.
abstract: Aiming at the problem of 3D surface reconstruction of small height objects, a method based on the scanning principle with thin structured light is proposed. The laser fringe is produced by a laser light source. It scans the surface of small height object under the control of a precise motion control system, and is integrated with a stereo light microscope and two cameras to form a complete structured light profilometry system. This method is very suitable for 3D surface reconstruction of small height objects. In order to deal with the phenomenon of "cracking" and local uneven brightness in microscope fringe image, the fringe image sequence is captured under different camera exposure parameters, and the quality of fringe image is improved by image fusion. The location of pixels on the center line of laser stripes is detected by the Loess local second order fitting method, and the positions of these pixels are smoothed and predicted by using the Lowess local linear fitting method. The deformation of the laser stripe center curve is calculated by constructing a baseline, and the 3D surface reconstruction of the object with small height is realized in the image space. Taking the small characters on the surface of Chinese coins and human hair as test samples, their 3D surfaces are constructed by using the method proposed in this paper. The reconstructed 3D surface shapes are highly consistent with the real 3D surface shapes of objects.

title: Establishment of Quality Detection and 3D Evaluation Model of Wool Fabric Based on Machine Vision
abstract: A method for detecting the surface quality of fluff fabrics based on machine vision using MATLAB is proposed. The original fluff and roller axial cutaways were obtained by the principle of light cutting imaging. The maximum inter class variance method and morphological method were used to segment the fluff region. The Canny operator effectively extracted the upper edge contour and thickness reference line of the fluff region. The thickness parameter in the vertical direction of the pile region and the coverage degree parameter model in the horizontal direction are established in three dimensions, and the surface quality of the pile fabric is comprehensively evaluated by parameters in two directions. We use MATLAB to obtain the three dimensional shape of the surface of the fluff fabric, in order to comprehensively analyze and evaluate the surface quality of the fluff.

title: Research on Point Cloud Repair Based on Multi parameter Extraction in Digital Power Plant
abstract: The 3D visualization of the traditional power plant can integrate the information in the scene and manage each area accurately and quickly. The surface missing parts and holes in the reconstruction process of 3D visualization power plant can lead to the loss of information. To solve this problem, an efficient holes repairing algorithm is proposed in this paper. Through the feature discrimination of the original data to simplify processing, and then repair the hole. In the case of retaining the characteristics of the original data, the subsequent repairing efficiency is improved by reducing the number of point clouds. After fast triangulation of the discrete data, a complete network is formed by least square fitting, and then the curvature change of the surface is minimized to make it follow the trend of curvature change around the hole. The experimental results show that this method can greatly improve the repair efficiency of point cloud hole data with a large number of point clouds, and retain its original features.

title: Segmentation Algorithm for 3D LiDAR Point Cloud Based on Region Clustering
abstract: Environmental perception is a key technology in autonomous cars and mobile robotics system. The clustering and segmentation of the point cloud data obtained by sensors is an important step to realize environmental perception. In order to solve the shortcomings of over segmentation in some current segmentation algorithms, a fast segmentation algorithm for 3D LIDAR cloud points is proposed. The Ground Plane Fitting algorithm is used to segment the ground surface, remove the ground cloud points interference, and combine the spatial Euclidean distance parameter with the angle parameter of the adjacent scan line of the LIDAR to cluster and segment the non ground cloud points. The experimental result show that compared with some traditional algorithms, this method can effectively reduce the segmentation error rate, improve the accuracy of non ground target segmentation, and significantly improve the segmentation efficiency.

title: FSAT A fracture surface analysis toolbox in MATLAB to compare 2D and 3D surface measures
abstract: A quantitative description of fracture surface morphology is crucial but cumbersome. Surface morphology influences important rock joint behavior, such as shear strength, fluid flow, contaminant transport and heat transfer. And while there are many suggestions and comparisons of roughness parameters, those are usually not considered in models and experiments dealing with surface roughness. This makes those experiments and simulations difficult to reproduce and compare. Here, we present a MATLAB toolbox called FSAT to calculate the most common roughness parameters. FSAT provides scientists with an easy and accessible method to quantitatively describe the surface and aperture characteristics of any given fracture independent of its geometrical dimension. Using FSAT, we investigate differences and similarities between roughness parameters that split a surface in profiles to surface measures that address triangulation based surfaces. For this, we split 10 samples of two types of sandstone, scanned their surfaces and determined their hydraulic aperture using Darcy tests. While surface measures are very sensitive to different rock types and allow a good separation between samples, profile parameters quantify more distinct features of the surface, allow analysis of anisotropy and give an overview about a surfaces heterogeneity by their statistical variation across a surface.

title: RTExtract: time series NMR spectra quantification based on 3D surface ridge tracking
abstract: Time series nuclear magnetic resonance (NMR) has advanced our knowledge about metabolic dynamics. Before analyzing compounds through modeling or statistical methods, chemical features need to be tracked and quantified. However, because of peak overlap and peak shifting, the available protocols are time consuming at best or even impossible for some regions in NMR spectra.  We introduce Ridge Tracking based Extract (RTExtract) a computer vision based algorithm, to quantify time series NMR spectra. The NMR spectra of multiple time points were formulated as a 3D surface. Candidate points were first filtered using local curvature and optima, then connected into ridges by a greedy algorithm. Interactive steps were implemented to refine results. Among 173 simulated ridges, 115 can be tracked (RMSD 0.001) For reproducing previous results, RTExtract took less than 2 h instead of ~48 h, and two instead of seven parameters need tuning. Multiple regions with overlapping and changing chemical shifts are accurately tracked. Availability and implementation Source code is freely available within Metabolomics toolbox GitHub repository (https:/github.com/artedison/Edison_Lab_Shared_Metabolomics_UGA/tree/master/metabolomics_toolbox/code/ridge_tracking) and is implemented in MATLAB and R. Supplementary information Supplementary data are available at Bioinformatics online.

title: Pre Processing and Surface Reconstruction of Points Cloud Based on Chord Angle Algorithm Technique
abstract: Although the rapid development in reverse engineering techniques, 3D laser scanners can be considered the modern technology used to digitize the 3D objects, but some troubles may be associate this process due to the environmental noises and limitation of the used scanners. So, in the present paper a data pre processing algorithm has been proposed to obtain the necessary geometric features and mathematical representation of scanned object from its point cloud which obtained using 3D laser scanner (Matter and Form) through isolating the noised points. The proposed algorithm based on continuous calculations of chord angle between each adjacent pair of points in point cloud. A MATLAB program has been built to perform the proposed algorithm which implemented using a suggested case studies with cylinder and dome shape. The resulted point cloud from application the proposed algorithm and result of surface fitting for the case studies has been proved the proficiency of the proposed chord angle algorithm in pre processing of data points and clean the point cloud, where the percent of data which was ignored as noisy data points according to proposed chord angle algorithm was arrived to (81.52% and (75.01%)of total number of data points in point cloud for first and second case study respectively.

title: Visualization of Non uniformly Distributed Measuring Data of 3D Surface Based on MATLAB
abstract: A kind of method to achieve visualization of non uniformly distributed measuring data of 3D surface in MATLAB environment was introduced.Using associated functions supplied by MATLAB,uniformly distributed coordinates were determined according to raw data.height coordinates at each uniformly distributed coordinates were calculated out by means of fitting and interpolation,non uniformly sampled measuring data was transformed to uniformly distributed data,and visualization was achieved using 3D visualization functions supplied by MATLAB.