{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T00:17:16Z","timestamp":1760228236891,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2022,5,10]],"date-time":"2022-05-10T00:00:00Z","timestamp":1652140800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Fundamental Research Funds for the Central Universities","award":["2572017CB13","YQ2020C018"],"award-info":[{"award-number":["2572017CB13","YQ2020C018"]}]},{"name":"Heilongjiang Provincial Natural Science Foundation of China","award":["2572017CB13","YQ2020C018"],"award-info":[{"award-number":["2572017CB13","YQ2020C018"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Tree height is an essential indicator in forestry research. This indicator is difficult to measure directly, as well as wind disturbance adds to the measurement difficulty. Therefore, tree height measurement has always been an issue that experts and scholars strive to improve. We propose a tree height measurement method based on tree fisheye images to improve the accuracy of tree height measurements. Our aim is to extract tree height extreme points in fisheye images by proposing an improved lightweight target detection network YOLOX-tiny. We added CBAM attention mechanism, transfer learning, and data enhancement methods to improve the recall rate, F1 score, AP, and other indicators of YOLOX-tiny. This study improves the detection performance of YOLOX-tiny. The use of deep learning can improve measurement efficiency while ensuring measurement accuracy and stability. The results showed that the highest relative error of tree measurements was 4.06% and the average relative error was 1.62%. The analysis showed that the method performed better at all stages than in previous studies.<\/jats:p>","DOI":"10.3390\/s22103636","type":"journal-article","created":{"date-parts":[[2022,5,10]],"date-time":"2022-05-10T21:52:11Z","timestamp":1652219531000},"page":"3636","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Fisheye Image Detection of Trees Using Improved YOLOX for Tree Height Estimation"],"prefix":"10.3390","volume":"22","author":[{"given":"Jiayin","family":"Song","sequence":"first","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Yue","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Wenlong","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6030-9523","authenticated-orcid":false,"given":"Hongwei","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Di","family":"Zhu","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Qiqi","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Yiming","family":"Fan","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]},{"given":"Chao","family":"Lu","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"106385","DOI":"10.1016\/j.buildenv.2019.106385","article-title":"Impacts of tree-planting pattern and trunk height on the airflow and pollutant dispersion inside a street canyon","volume":"165","author":"Huang","year":"2019","journal-title":"Build. 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