A method of ray tracing for free-form optical surfaces has been developed. The ray tracing through such surfaces is based on Delaunay triangulation of the discrete data of the surface and is related to finite-element modeling. Some numerical examples of applications to analytical, noisy, and experimental free-form surfaces (in particular, a corneal topography map) are presented. Ray-tracing res...

Background: A comprehensive database, comprising geometry and properties of human teeth, is needed for dentistry education and dental research. The aim of this study was to create a three-dimensional model of human teeth to improve the dental E-learning and dental research.   Methods: In this study, a cross-section picture of the three-dimensional model of the teeth was used. CT-Scan im...

To study multi-fractal behavior of corroded steel surface, a range of fractal surfaces of corroded surfaces of Q235 steel were constructed by using the Weierstrass-Mandelbrot method under a high total accuracy. The multi-fractal spectrum of fractal surface of corroded steel was calculated to study the multi-fractal characteristics of the W-M corroded surface. Based on the shape feature of the m...

The corrosion inhibition efficiency of benzimidazole, 2-methylbenzimidazole and 2- aminobenzimidazole for mild steel immersed in 3.5 NaCl solution was investigated by electrochemical impedance spectroscopy EIS at concentration range from 10-5 to 10-2 M of imidazoles and temperature range from 30 to 50°C. In addition, DC polarization was examined to determine inhibition mechanism at concentratio...

In this paper, we describe a method for overlaying a texture onto a T-shirt, for improving current virtual fitting system. In such systems, users can try on clothes virtually. In order to realize such a system, a depth camera has been used. These depth cameras can capture 3D data in real time and have been used by some industrial virtual cloth fitting systems. However, these systems roughly, or...

The local model fitting (LMF) method is a useful single-shot surface profiling algorithm that features fast measurement speed and robustness against vibration. However, the measurement range of the LMF method (i.e., measurable height difference between two neighboring pixels) is limited up to a quarter of the light source wavelength. To cope with this problem, the multiwavelength-matched LMF(MM...

Data reduction tools are developed and evaluated using a data analysis framework. Simple and intelligent thinning algorithms are applied to both synthetic and real data and the thinned datasets are ingested into an analysis system. A major problem of data reduction is that certain types of camera or scanner produce vast amounts of data, the processing of which presents serious problems. Rather ...

Let a family of curves or surfaces be given in parametric form via the model equation x =J‘(s, /I), where x E R”, p E KY’, and s E S c [wd. d < n. We present an algorithm for solving the problem: Find a shape cec’tor p* such that the manlfold M* = (f(s, /I*): s E S) is a best fir to scattered data :z, j ,‘= , c R” in the Sense that, jbr some is* )y=, , the sum of the squared least distances )-y...

Recent years have seen an increasing interest in algebraic curves and surfaces of high degree as geometric models or shape descriptors for model-based computer vision tasks such as object recognition and position estimation. Although their invariant-theoretic properties them a natural choice for these tasks, fitting algebraic curves and surfaces to data sets is difficult, and fitting algorithms...

We investigate different techniques for fitting Bézier curves to surfaces in context of high-order curvilinear mesh generation. Starting from distance-based least-squares fitting we develop an incremental algorithm, which incorporates approximations of stretch and bending energy. In the process, the algorithm reduces the energy weight in favor of accuracy, leading to an optimized set of samplin...