New spectrum ratio properties and features for shadow detection

CORC > 沈阳自动化研究所 > 中国科学院沈阳自动化研究所 > 机器人学研究室

	New spectrum ratio properties and features for shadow detection
	Tian JD(田建东); Qi XJ(齐虓隽); Qu LQ(屈靓琼); Tang YD(唐延东)
刊名	Pattern Recognition
	2016
卷号	51 期号:3 页码:85–96
关键词	Spectrum ratio properties Shadow features Skylight SPD Daylight SPD Shadow detection
ISSN号	0031-3203
通讯作者	田建东
产权排序	1
中文摘要	Successfully detecting shadows in still images is challenging yet has wide applications. Shadow properties and features are very important for shadow detection and processing. The aim of this work is to find some new physical properties of shadows and use them as shadow features to design an effective shadow detection method for outdoor color images. We observe that although the spectral power distribution (SPD) of daylight and that of skylight are quite different, in each channel, the spectrum ratio of the point-wise product of daylight SPD with sRGB color matching functions (CMFs) to the point-wise product of skylight SPD with sRGB CMFs roughly approximates a constant. This further leads to that the ratios of linear sRGB pixel values of surfaces illuminated by daylight (in non-shadow regions) to those illuminated by skylight (in shadow regions) equal to a constant in each channel. Following this observation, we calculated the spectrum ratios under various Sun angles and further found out four new shadow properties. With these properties as shadow features, we developed a simple shadow detection method to quickly locate shadows in single still images. In our method, we classify an edge as a shadow or non-shadow edge by verifying whether the pixel values on both sides of the Canny edges satisfy the three shadow verification criteria derived from the shadow properties. Extensive experiments and comparison show that our method outperforms state-of-the-art shadow detection methods.
WOS标题词	Science & Technology ; Technology
类目[WOS]	Computer Science, Artificial Intelligence ; Engineering, Electrical & Electronic
研究领域[WOS]	Computer Science ; Engineering
关键词[WOS]	CAST SHADOWS ; MODEL ; REMOVAL ; CALIBRATION ; SURFACE ; IMAGES
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000367633400007
内容类型	期刊论文
源URL	[http://ir.sia.cn/handle/173321/17439]
专题	沈阳自动化研究所_机器人学研究室
推荐引用方式 GB/T 7714	Tian JD,Qi XJ,Qu LQ,et al. New spectrum ratio properties and features for shadow detection[J]. Pattern Recognition,2016,51(3):85–96.
APA	Tian JD,Qi XJ,Qu LQ,&Tang YD.(2016).New spectrum ratio properties and features for shadow detection.Pattern Recognition,51(3),85–96.
MLA	Tian JD,et al."New spectrum ratio properties and features for shadow detection".Pattern Recognition 51.3(2016):85–96.