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1. 3D Image Correction of Tilted Sample Through Coordinate Transformation
Wei Chu, Joseph Fu, Ronald G Dixson, Theodore Vincent Vorburger
In scanned probe measurements of micrometer- or nanometer-scale lines, it is nearly impossible to maintain the sample in a perfectly level position, and even a small amount of tilt angle can contribute to the accuracy of the result of measurand such ...
2. A moving window correlation method to reduce the distortion of SPM images
Wei Chu, Joseph Fu, Ronald G Dixson, Ndubuisi George Orji, Theodore Vincent Vorburger
Many scanning probe microscopes (SPMs), such as the scanning tunneling microscope (STM) and atomic force microscope (AFM), use piezoelectric actuators operating in open loop for generating the scans of the surfaces. However, nonlinearities mainly cau ...
3. A simple and fast spline filtering algorithm for surface metrology
Hao H. Zhang, Daniel B Ott, Jun-Feng Song, Mingsi Tong, Wei Chu
The spline filters and the corresponding robust filters are commonly used filters recommended
in ISO standards for surface evaluation. Generally, these linear and non-linear spline filters,
composed of symmetric, positive-definite matrices, are a ...
4. An Areal Isotropic Spline Filter for Surface Metrology
Journal of Research (NIST JRES)
Hao H. Zhang, Mingsi Tong, Wei Chu
This paper deals with the application of the spline filter as an areal filter for surface
metrology. A profile (2D) filter is often applied in orthogonal directions to yield an areal
filter for a three-dimensional (3D) measurement. Unlike the Gau ...
5. An Image Stitching Method to Eliminate the Distortion of the Sidewall in Linewidth Measurement
Xuezeng Zhao, Joseph Fu, Wei Chu, C Nguyen, Theodore Vincent Vorburger
Nano-scale linewidth measurements are performed in semiconductor manufacturing, the data storage industry, and micro-mechanical engineering. It is well known that the interaction of probe and sample affects the measurement accuracy of linewidth measu ...
6. An Improved Algorithm of Congruent Matching Cells (CMC) Method for Firearm Evidence Identifications
Mingsi Tong, Jun-Feng Song, Wei Chu
The Congruent Matching Cells (CMC) method was invented at the National Institute of Standards and
Technology (NIST) for firearm evidence identifications. The CMC method divides the entire image into small correlation cells and uses three sets of fo ...
7. An Improved Digital Image Correlation Method Applied to Scanning Probe Microscope Images
Wei Chu, Joseph Fu, Theodore Vincent Vorburger
Digital image correlation (DIC) is a method for measuring the surface displacements and displacement gradients in materials under deformation. During the calculation, the traditional DIC method directly uses the intensity values of compared images an ...
8. An Iterative Image Registration Algorithm by Optimizing Similarity Measurement
Wei Chu, Li Ma, Jun-Feng Song, Theodore Vincent Vorburger
9. Applications of Cross-Correlation Functions
Theodore Vincent Vorburger, Jun-Feng Song, Wei Chu, Li Ma, Xiaoyu A Zheng, Thomas B Renegar, Son H Bui
We describe several examples where we use cross-correlation functions to quantify the similarity of 2D surface profiles or of 3D surface topography images. The applications have included 1) the manufacture of Standard Reference Material (SRM) bullet ...
10. Automatic Identification of Bullet Signatures Based on Consecutive Matching Striae (CMS) Criteria
Wei Chu, Robert Meryln Thompson, Jun-Feng Song, Theodore Vincent Vorburger
The consecutive matching striae (CMS) numeric criteria for firearm and toolmark identifications have been widely accepted by forensic examiners, although there have been questions concerning its observer subjectivity and limited statistical support. ...