運用影像辨識法比較行人道綠視率對熱環境之影響

Comparison of the Effect of Pedestrian Visible Green Index on Thermal Environment Using Image Recognition Method

綠化的三維指標以綠視率為主，該指標顯示出行人正常視野裡綠化面積所占的比例。行人步道綠視率高低與熱環境品質的溫度、舒適度等指標之相關性尚待研究。因此，本文透過行人步行過程中以人體正常視角下拍攝行人步道實景影像及熱影像，並且同時測量溫度及濕度等資料，進而應用Visual Basic撰寫影像識別程式，解析每張影像之綠視率及熱影像表面溫度（surface temperature）等，結合空氣溫度（air temperature）及濕度，進一步比較行人綠化視覺體驗環境與都市溫度、濕度等熱環境之間的關係，評估行人的熱舒適度。研究成果顯示，綠視率越高熱像表面溫度值越低、空氣溫度愈低且舒適度愈佳。反之綠視率越低則熱環境品質越差。因而，提高行人道的綠視率確能緩解都市熱環境溫度，提升行人的舒適度。

The three-dimensional indicator of greening is mainly visible green index, which shows the proportion of greening area in the normal vision of travelers. The correlation between pedestrian visible green index and thermal environmental quality, temperature, comfort and other environmental quality remains to be studied. Therefore, in this paper, the real image and thermal image of pedestrian walkway are taken from the normal perspective of human body during pedestrian walking, and the temperature and humidity are measured at the same time. Then, the image recognition program is written by visual basic to analyze the green visual rate and thermal image temperature of each image, and combined with air temperature and humidity. Further compare the relationship between pedestrian greening visual experience environment and urban temperature, humidity and other thermal environment, and evaluate the thermal comfort of pedestrians. The research results show that the higher the visible green index, the lower the surface temperature of thermal image, the lower the air temperature and the better comfortable. On the contrary, the lower the green visibility, the worse the space quality of thermal environment. Therefore, improving the green visibility of sidewalks can alleviate the urban thermal environment temperature and improve the comfort of pedestrians.