Algorithms of Automatic Image Measure System

Zhang, Wu-jie; Zha, ShiHua; Li, Di; Wang, Xu

doi:10.1109/icia.2006.305851

Cited by 3 publications

(3 citation statements)

References 4 publications

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“…Nayar and Nakagawa, 1994;Crete et al, 2007;Gamadia, 2006;Lee et al, 2001;Zhang, 2006;Morrison et al, 2007;Wee and Paramesran, 2007;Huang and Jing, 2007;Krotov, 1987;Subbarao and Tyan, 1998), we are not aware of previous similar studies on thermal imagery.…”

Section: Introductionmentioning

confidence: 77%

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On the focusing of thermal images

Faundez-Zanuy

Mekyska

Espinosa-Duro

2011

Pattern Recognition Letters

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Section: Introductionmentioning

confidence: 77%

“…While there is a considerable amount of work done on visible images[1][2][3][4][5][6][7][8], we are not aware about studies on thermal images. .…”

mentioning

confidence: 99%

On the focusing of thermal images

Faundez-Zanuy

Mekyska

Espinosa-Duro

2011

Pattern Recognition Letters

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“…It determines the circle centre and radius by locating a part of boundary point on the circle. The calculation of the geometric parameters by Zhang et al 24 is used in this step.…”

Section: Image Recognitionmentioning

confidence: 99%

A non-contact method to measure the difference between the left wheelbase and the right wheelbase for dynamic vehicle detection

Yue

Shan

2015

Proceedings of the Institution of Mechanical Engineers, Part D:

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The measurement of the difference between the left wheelbase and the right wheelbase is the most important part of vehicle detection. A large difference between the left wheelbase and the right wheelbase may lead to a serious traffic accident. This paper develops a new method for dynamic detection, which is based on binocular stereo vision and is a non-contact method that can reduce the equipment failure rate. A real vehicle experiment is performed to verify the proposed method. The manual measurement method and the photosensitive detection method are applied for comparison. The experimental results demonstrate that the proposed method is more stable than the manual measurement method and the photosensitive detection method, and the proposed method can also be extended to other vehicles. Thus, the proposed method is useful for vehicle detection.

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Implementation of autofocus in alignment system for layered imprint fabrication

Wang

Duan

et al. 2009

Trans. Tianjin Univ.

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Abstract：Autofocus method based on the analysis of image content information is investigated to reduce the alignment error resulting from mark positioning uncertainty due to defocus in microstructure layered fabrication process based on multilevel imprint lithography. The applicability of several autofocus functions to the alignment mark images is evaluated concerning their uniformity, sharpness near peak, reliability and measure computation efficiency and the most suitable one based on power spectrum in frequency domain (PSFD) is adopted. To solve the problem of too much computation amount needed in PSFD algorithm, the strategy of interested region detection and effective image reconstruction is proposed and the algorithm efficiency is improved. The test results show that the computation time is reduced from 0.316 s to 0.023 s under the same conditions while the other merits of the function are preserved, which indicates that the modified algorithm can meet the mark image autofocusing requirements in response time, accuracy and robustness. The alignment error due to defocus which is about 0.5 μm indicated by experimental results can be reduced or eliminated by the autofocusing implementation. Keywords：autofocus algorithm; alignment; imprint lithography; layered fabrication Three-dimensional microstructure fabrication techniques are important for a variety of applications since fabrication in the third dimension facilitates higher speed, higher packing density, less energy loss, more efficient reaction, etc [1,2] . The final goal of our research is to develop a set of standard 3D microstructure fabrication process based on multilevel imprint lithography which is an efficient, low cost and high resolution method for the parallel replica of microstructures [3,4] . One of the critical issues of the multilevel imprint is the precision alignment between layers. So an alignment system with a resolution of 0.2 μm and an overlay accuracy of 1.5 μm based on video image is developed.Since the depth of the field of microlens is very short in the alignment system with an alignment accuracy of micros or sub-micros, it is necessary to focus the alignment mark carefully to obtain a clear image. When focusing manually, defocus error will be generated due to individual evaluation criteria for well-focused image. Moreover, to attenuate the influence of temperature variation and cycling airflow on accuracy, the alignment setup should be placed in a closed enclosure, which makes it difficult to focus manually. So it is necessary to construct or choose an autofocus function suitable for the specific system. In this paper, several autofocus algorithms are compared concerning their applicability to the mark images and the optimal one is adopted and modified. The improved focusing algorithm is applied to the alignment system.

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Algorithms of Automatic Image Measure System

Cited by 3 publications

References 4 publications

On the focusing of thermal images

On the focusing of thermal images

A non-contact method to measure the difference between the left wheelbase and the right wheelbase for dynamic vehicle detection

Implementation of autofocus in alignment system for layered imprint fabrication

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