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A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity
The clarity evaluation function plays a vital role in the autofocus technique. The accuracy and efficiency of the image clarity evaluation function directly affects the accuracy of autofocus and the speed of focusing. However, classical clarity function values are sensitive to changes in background...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10675265/ https://www.ncbi.nlm.nih.gov/pubmed/38005405 http://dx.doi.org/10.3390/s23229017 |
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author | Wang, Xiaoyi Yao, Tianyang Liu, Mingkang Zheng, Kunlei Zhao, Chengxiang Xiao, Longyuan Zhu, Dongjie |
author_facet | Wang, Xiaoyi Yao, Tianyang Liu, Mingkang Zheng, Kunlei Zhao, Chengxiang Xiao, Longyuan Zhu, Dongjie |
author_sort | Wang, Xiaoyi |
collection | PubMed |
description | The clarity evaluation function plays a vital role in the autofocus technique. The accuracy and efficiency of the image clarity evaluation function directly affects the accuracy of autofocus and the speed of focusing. However, classical clarity function values are sensitive to changes in background brightness and changes in object contour length. This paper proposes a normalized absolute values adaptive (NAVA) evaluation function of image clarity. It can eliminate the influence of changes in background brightness and the length of the measured object contour on the image clarity function value. To verify the effectiveness of the NAVA function, several experiments were conducted under conditions of virtual master gear images and actual captured images. For actual captured images, the variation of the evaluation results of the NAVA function is far less than the corresponding variation of the classic clarity function. Compared with classical clarity evaluation functions, the NAVA function can provide normalized absolute clarity values. The correlations between the NAVA function results of image clarity and both the contour length and background brightness of the tested object are weak. The use of the NAVA function in automatic and manual focusing systems can further improve focusing efficiency. |
format | Online Article Text |
id | pubmed-10675265 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-106752652023-11-07 A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity Wang, Xiaoyi Yao, Tianyang Liu, Mingkang Zheng, Kunlei Zhao, Chengxiang Xiao, Longyuan Zhu, Dongjie Sensors (Basel) Article The clarity evaluation function plays a vital role in the autofocus technique. The accuracy and efficiency of the image clarity evaluation function directly affects the accuracy of autofocus and the speed of focusing. However, classical clarity function values are sensitive to changes in background brightness and changes in object contour length. This paper proposes a normalized absolute values adaptive (NAVA) evaluation function of image clarity. It can eliminate the influence of changes in background brightness and the length of the measured object contour on the image clarity function value. To verify the effectiveness of the NAVA function, several experiments were conducted under conditions of virtual master gear images and actual captured images. For actual captured images, the variation of the evaluation results of the NAVA function is far less than the corresponding variation of the classic clarity function. Compared with classical clarity evaluation functions, the NAVA function can provide normalized absolute clarity values. The correlations between the NAVA function results of image clarity and both the contour length and background brightness of the tested object are weak. The use of the NAVA function in automatic and manual focusing systems can further improve focusing efficiency. MDPI 2023-11-07 /pmc/articles/PMC10675265/ /pubmed/38005405 http://dx.doi.org/10.3390/s23229017 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Wang, Xiaoyi Yao, Tianyang Liu, Mingkang Zheng, Kunlei Zhao, Chengxiang Xiao, Longyuan Zhu, Dongjie A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title | A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title_full | A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title_fullStr | A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title_full_unstemmed | A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title_short | A Normalized Absolute Values Adaptive Evaluation Function of Image Clarity |
title_sort | normalized absolute values adaptive evaluation function of image clarity |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10675265/ https://www.ncbi.nlm.nih.gov/pubmed/38005405 http://dx.doi.org/10.3390/s23229017 |
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