基于鱼眼图像修正的天空视域因子计算方法
Sky View Factor Calculation Method Based on Fisheye Image Correction
摘要: 天空视域因子(SVF)是城市热环境的重要评价指标之一。利用鱼眼照片估计天空视域因子的方法快速准确,但深受等距投影的制约。在本研究中提出一种对鱼眼照片进行等距化畸变修正的方法,将任意投影模型的鱼眼镜头实拍图修正为等距投影下的图像,然后用Steyn算法计算SVF值。通过对比两组镜头的实验结果,说明非等距投影鱼眼镜头也能得到准确的SVF值,验证了该方法的精度和有效性。本文的方法具有很高的经济性、实用性,为城市热环境领域研究者及城市规划人员提供了便利。
Abstract: Sky View Factor (SVF) is one of the essential indicators for urban thermal environmental assess-ment. The method of estimating SVF using fisheye photographs is fast and accurate, but it is re-stricted by equidistant projections. This study proposes an equidistant distortion correction meth-od for fisheye photographs that can transform the fisheye lens photo of any projection model into the image under the equidistant projection. Then, SVF values are calculated using Steyn’s method. Comparing the experimental results of two groups of lenses shows that accurate SVF values can be obtained for a non-equidistant projection fisheye lens. The accuracy and validity of the method are verified. The method proposed in this article is highly economical and practical, providing conven-ience for researchers and urban planners in urban thermal environments.
文章引用:郑可欣, 孙梦瑶, 夏乐年, 娄方彦, 李亚男. 基于鱼眼图像修正的天空视域因子计算方法[J]. 测绘科学技术, 2024, 12(1): 39-46. https://doi.org/10.12677/GST.2024.121006

参考文献

[1] Eliasson, I. (1990) Urban Geometry, Surface Temperature and Air Temperature. Energy and Buildings, 15, 141-145. [Google Scholar] [CrossRef
[2] Oke, T.R. (1979) Boundary Layer Climates. Routledge, London, 227-302.
[3] 毛娅玲. 天空视域因子计算方法及城市热岛效应分析研究[D]: [硕士学位论文]. 张家口: 河北建筑工程学院, 2019.
[4] 任智慧. 基于SVF的哈尔滨典型街谷空间热环境优化模拟研究[D]: [硕士学位论文]. 哈尔滨: 哈尔滨工业大学, 2019.
[5] Frazer, G., Fournier, R., Trofymow, J., et al. (2001) A Comparison of Digital and Film Fisheye Photography for Analysis of Forest Canopy Structure and Gap Light Transmission. Agricultural and Forest Meteorology, 109, 249-263. [Google Scholar] [CrossRef
[6] Li, G., Ren, Z. and Zhan, C. (2020) Sky View Factor-Based Correlation of Landscape Morphology and the Thermal Environment of Street Canyons: A Case Study of Harbin, China. Building and Environment, 169, Article ID: 106587. [Google Scholar] [CrossRef
[7] Oke, T.R. (1981) Canyon Geometry and the Urban Heat Island Comparison of Scale Model and Field Observations. Journal of Climatology, 1, 237-254. [Google Scholar] [CrossRef
[8] Johnson, G.T. and Watson, I.D. (1984) The Determination of View-Factors in Ur-ban Canyons. Journal of Applied Meteorology and Climatology, 23, 329-335. [Google Scholar] [CrossRef
[9] Chapman, L., Thornes, J.E. and Bradley, A.V. (2002) Sky-View Factor Approximation Using GPS Receivers. International Journal of Climatology, 22, 615-621. [Google Scholar] [CrossRef
[10] Matzarakis, A. and Matuschek, O. (2011) Sky View Factor as a Parameter in Applied Cli-matology Rapid Estimation by the SkyHelios Model. Meteorologische Zeitschrift, 20, 39-45. [Google Scholar] [CrossRef
[11] Carrasco-Hernandez, R., Smedley, A.R.D. and Webb, A.R. (2015) Using Urban Canyon Geometries Obtained from Google Street View for Atmospheric Studies: Potential Applications in the Calculation of Street Level Total Shortwave Irradiances. Energy and Buildings, 86, 340-348. [Google Scholar] [CrossRef
[12] Hu, C.-B., Zhang, F., Gong, F.-Y., et al. (2020) Classification and Mapping of Urban Canyon Geometry Using Google Street View Images and Deep Multitask Learning. Building and Environment, 167, Article ID: 106424. [Google Scholar] [CrossRef
[13] Herbert, T.J. (1986) Calibration of Fisheye Lenses by Inversion of Area Projections. Applied Optics, 25, 1875-1876. [Google Scholar] [CrossRef
[14] Zeng, L., Lu, J., Li, W., et al. (2018) A Fast Approach for Large-Scale Sky View Factor Estimation Using Street View Images. Building and Environment, 135, 74-84. [Google Scholar] [CrossRef
[15] Steyn, D.G. (1980) The Calculation of View Factors from Fisheye-Lens Photographs: Research Note. Atmosphere-Ocean, 18, 254-258. [Google Scholar] [CrossRef
[16] Matzarakis, A., Rutz, F. and Mayer, H. (2007) Modelling Radiation Fluxes in Simple and Complex Environments— Application of the RayMan Model. International Journal of Biometeorology, 51, 323-334. [Google Scholar] [CrossRef] [PubMed]
[17] Chapman, L., Thornes, J.E. and Bradley, A.V. (2001) Rapid Determination of Canyon Geometry Parameters for Use in Surface Radiation Budgets. Theoretical and Applied Climatology, 69, 81-89. [Google Scholar] [CrossRef
[18] Honjo, T., Tzu-Ping, L.I.N. and Seo, Y. (2019) Sky View Factor Measurement by Using a Spherical Camera. Journal of Agricultural Meteorology, 75, 59-66. [Google Scholar] [CrossRef
[19] Grimmond, C.S.B., Potter, S.K., Zutter, H.N., et al. (2001) Rapid Methods to Estimate Sky-View Factors Applied to Urban Areas. International Journal of Climatology, 21, 903-913. [Google Scholar] [CrossRef
[20] Clark, J.A. and Follin, G.M. (1988) A Simple “Equal Area” Calibration for Fisheye Photog-raphy. Agricultural and Forest Meteorology, 44, 19-25. [Google Scholar] [CrossRef