Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "fringe pattern" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
An exact approach for radius of curvature measurement in a calibration test sphere
Autorzy:
Jalife-Chavira, Jaime M.
Trujillo-Schiaffino, Gerardo
Mendoza-Villegas, Paloma G.
Salas-Peimbert, Didia P.
Anguiano-Morales, Marcelino
Corral-Martínez, Luis F.
Zendejas-Hernández, Edgar
Powiązania:
https://bibliotekanauki.pl/articles/2086760.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
keratometry
radius of curvature
diopter
cosine fringe pattern
film
Opis:
In this paper we present a technique to measure the radius of curvature of a test sphere based on the relation between acquired images of a circular cosine fringe pattern and size of virtual image formed on the calibration test surface. Radius of curvature is calculated with the exact equation proposed, using the parameters of the optical setup. Fringe pattern evaluation was performed by locating extrema indices. The mathematical formulation as well as the experimental setup and results are presented. After applying a linear fit algorithm to the data as a method of compensation, obtained results show an error within the tolerance established by the ISO 10343 specifications.
Źródło:
Optica Applicata; 2022, 52, 2; 229--242
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neural network model for phase-height relationship of each image pixel in 3D shape measurement by machine vision
Autorzy:
Chung, B
Powiązania:
https://bibliotekanauki.pl/articles/173298.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
machine vision
shape measurement
fringe pattern projection
phase-height relationship
neural network
Opis:
In a three-dimensional measurement system based on a digital light processing projector and a camera, a height estimating function is very important. Sinusoidal fringe patterns of the projector are projected onto the object, and the phase of the measuring point is calculated from the camera image. Then, the height of the measuring point is inferred by the phase. The phase-to-height relationship is unique at each image point. However it is nonlinearly different according to the image coordinates. It is also difficult to obtain the geometrical model because of lens distortion. Even though some studies have been performed on neural network models to find the height from the phase and the related coordinates, the results are not good because of the complex relationship. Therefore, this paper proposes a hybrid method that combines a geometric analysis and a neural network model. The proposed method first finds the phase-to-height relationship from a geometric analysis for each image pixel, and then uses a neural network model to find the related parameters for the relationship. The experimental results show that the proposed method is superior to previous neural network methods.
Źródło:
Optica Applicata; 2014, 44, 4; 587-599
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One shot profilometry using iterative two-step temporal phase-unwrapping
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173912.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
composite fringe pattern
Fourier transform
two-step temporal phase-unwrapping
Opis:
This paper reviews two techniques that have been recently published for three-dimensional profilometry and proposes one shot profilometry using iterative two-step temporal phase-unwrapping by combining the composite fringe projection and the iterative two-step temporal phase unwrapping algorithm. In temporal phase unwrapping, many images with different frequency fringe pattern are needed to project, which would take much time. In order to solve this problem, Ochoa proposed a phase unwrapping algorithm based on phase partitions using a composite fringe. However, we found that the fringe order determined through the construction of phase partitions tended to be imprecise. Recently, we proposed an iterative two-step temporal phase unwrapping algorithm, which can achieve high sensitivity and high precision shape measurement. But it needs multiple frames of fringe images which would take much time. In order to take into account both the speed and accuracy of three-dimensional shape measurement, we get a new, and more accurate unwrapping method based on a composite fringe pattern by combining these two techniques. This method not only retains the speed advantage of Ochoa’s algorithm, but also greatly improves its measurement accuracy. Finally, the experimental evaluation is conducted to prove the validity of the proposed method.
Źródło:
Optica Applicata; 2017, 47, 1; 97-110
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies