A 3D Measurement Method Based on Three Frequencies PSP

2014 ◽  
Vol 701-702 ◽  
pp. 471-474
Author(s):  
Li Mei Song ◽  
Guang Xin Xing ◽  
Peng Qiang Wang ◽  
Jiang Tao Xi ◽  
Qing Hua Guo
Keyword(s):  
3D Reconstruction ◽  
Precision Measurement ◽  
Measurement Method ◽  
Three Dimensional ◽  
Trigonometric Function ◽  
Phase Unwrapping ◽  
Optical Information ◽  
3D Measurement ◽  
High Precision Measurement ◽  
3D Measurements

This paper proposes a method of global phase unwrapping used in multi-frequency three-dimensional (3D) measurements. In this method, three kinds of optical information which change in accordance with trigonometric function (sine or cosine) to the objects. The optical information cycles is P1, P2 and P3. Each waveform should 4-8 steps phase shifts. Then, calculate the phase value of each cycle. The composited phase value of two cycles and the final composited phase value of three cycles are calculated by image shift of each cycle. Finally, calculate the global phase value of each cycle based on the composited phase, thus, all the 3D coordinates of objects can be obtain after 3D reconstruction. The proposed method can solves the object surfaces color changing largely in 3D measurements. This method realizes high precision measurement without spray developer and achieves the protection of the environment.

scholarly journals 3D Measurement of Human Chest and Abdomen Surface Based on 3D Fourier Transform and Time Phase Unwrapping

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1091 ◽  
Author(s):  
Haibin Wu ◽  
Shuang Yu ◽  
Xiaoyang Yu
Keyword(s):  
Fourier Transform ◽  
Phase Error ◽  
Three Dimensional ◽  
Image Sequences ◽  
Current Approach ◽  
Individual Characteristics ◽  
Phase Unwrapping ◽  
3D Measurement ◽  
Human Experiments ◽  
The Difference

Monitoring respiratory movements is an effective way to improve radiotherapy treatments of thoracic and abdominal tumors, but the current approach is limited to measuring specific points in the chest and abdomen. In this paper, a dynamic three-dimensional (3D) measurement approach of the human chest and abdomen surface is proposed, which can infer tumor movement more accurately, so the radiotherapy damage to the human body can be reduced. Firstly, color stripe patterns in the RGB color model are projected, then after color correction, the collected stripe image sequences are separated into the three RGB primary color stripe image sequences. Secondly, a fringe projection approach is used to extract the folded phase combined 3D Fourier transform with 3D Gaussian filtering. By the relationship between adjacent fringe images in the time sequence, Gaussian filter parameters with individual characteristics are designed and optimized to improve the accuracy of wrapped phase extraction. In addition, based on the difference between the fractional parts of the folded phase error, one remainder equation can be determined, which is used for time-phase unwrapping. The simulation model and human experiments show that the proposed approach can obtain the 3D image sequences of the chest and abdomen surface in respiratory motion effectively and accurately with strong anti-interference ability.

scholarly journals Development of a Micro/Nano Probing System Using Double Elastic Mechanisms

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4229 ◽  
Author(s):  
Rui-Jun Li ◽  
Peng Xu ◽  
Peng-Yu Wang ◽  
Kuang-Chao Fan ◽  
Rong-Jun Cheng ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Precision Measurement ◽  
Vertical Direction ◽  
3D Measurement ◽  
Connecting Rod ◽  
High Precision Measurement ◽  
Coordinate Measurement ◽  
Coordinate Measurement Machine ◽  
System A ◽  
Elastic Mechanism

To meet the requirement of high precision measurement of coordinate measurement machine system, a compact microprobe has been designed for 3D measurement in this paper. Aiming to reduce the influences of signal coupling during the probing process, the probe has been designed by adopting two elastic mechanisms, in which the horizontal and vertical motions of the probe tip can be separated by differential signals of quadrant photodetectors in each elastic mechanism. A connecting rod has been designed to transfer the displacement of the probe tip in vertical direction from lower to upper elastic mechanisms. The sensitivity models in horizontal and vertical directions have been established, and the sensor sensitivity has been verified through experiments. Furthermore, the signal coupling of three axes has been analyzed, and mathematical models have been proposed for decoupling. The probing performance has been verified experimentally.

scholarly journals Comparative study of glenoid version and inclination using two-dimensional images from computed tomography and three-dimensional reconstructed bone models

2020 ◽  
Vol 23 (3) ◽  
pp. 119-124
Author(s):  
Chang-Hyuk Choi ◽  
Hee-Chan Kim ◽  
Daewon Kang ◽  
Jun-Young Kim
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Ct Scans ◽  
3D Measurement ◽  
Two Dimensional ◽  
Glenoid Version ◽  
Observer Reliability ◽  
3D Measurements ◽  
Orthopedic Surgeons ◽  
2D Images

Background: This study was performed to compare glenoid version and inclination measured using two-dimensional (2D) images from computed tomography (CT) scans or three-dimensional (3D) reconstructed bone models.Methods: Thirty patients who had undergone conventional CT scans were included. Two orthopedic surgeons measured glenoid version and inclination three times on 2D images from CT scans (2D measurement), and two other orthopedic surgeons performed the same measurements using 3D reconstructed bone models (3D measurement). The 3D-reconstructed bone models were acquired and measured with Mimics and 3-Matics (Materialise).Results: Mean glenoid version and inclination in 2D measurements were –1.705º and 9.08º, respectively, while those in 3D measurements were 2.635º and 7.23º. The intra-observer reliability in 2D measurements was 0.605 and 0.698, respectively, while that in 3D measurements was 0.883 and 0.892. The inter-observer reliability in 2D measurements was 0.456 and 0.374, respectively, while those in 3D measurements was 0.853 and 0.845.Conclusions: The difference between 2D and 3D measurements is not due to differences in image data but to the use of different tools. However, more consistent results were obtained in 3D measurement. Therefore, 3D measurement can be a good alternative for measuring glenoid version and inclination.

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