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原文传递 ASSESSMENT OF VISIBILITY ON ROADS UNDER SNOW CONDITIONS USING DIGITAL IMAGES.

题名：	ASSESSMENT OF VISIBILITY ON ROADS UNDER SNOW CONDITIONS USING DIGITAL IMAGES.
作者：	Hagiwara-T; Fujita-S; Kizaka-K
关键词：	Digital-cameras; Image-processing; Japan-; Luminance-; Power-spectra; Snow-; Snowstorms-; Traffic-control; Visibility-
摘要：	It is important to adequately assess visibility on roads during severe snowstorms so that this information can be provided to motorists and road administrators. This paper examines basic methods of assessing poor visibility by using images from a road monitoring camera. An experiment was performed during a 30-day period in 2001 in the suburbs of Sapporo City, Hokkaido, Japan. Image, illuminance and visibility in snowstorm were recorded at two-minute intervals. Under low visibility, there was little contrast within each image from the monitoring camera, and linear elements in the image tended not to be visible. The gray levels of the images were extracted in high and low visibility. The pixel contrast of a target that was selected on a road was examined in the image. Then the characteristics of the frequencies of extracted gray levels were examined after two-dimensional Fourier transform. The results suggest that assessment of snowstorm-induced low visibility will be enabled by the development of an algorithm that uses pixel contrast and the characteristics of power spectrum identified from images taken by a road monitoring camera.
总页数：	Conference Title: 11th International Road Weather Conference. Location: Sapporo, Japan. Sponsored by: Standing International Road Weather Commission. Held: 20020126-20020128. 2002/01. pp7
报告类型：	科技报告