People identification using shadow dynamics

Yumi Iwashita, Adrian Stoica, Ryo Kurazume

Research output: Chapter in Book/Report/Conference proceedingConference contribution

14 Citations (Scopus)


People identification has numerous applications, ranging from surveillance/security to robotics. Face and body movement/ gait biometrics are the most important tools for this task. Traditional biometrics use direct observation of the body, yet in some situations a projection may offer more information than the direct signal, for example the shadow of a person observed from overhead, e.g. from an unmanned aerial vehicle, may contain more detail than the top view of the head/body. We introduced the idea of shadow biometrics, exploiting biometrics information in human shadow silhouettes as derived from video imagery; this enables "overhead biometrics", for recognition of human identity and behavior from high altitude airborne platforms using overhead video sequences. In this paper, we provide a demonstration of person identification based on gait recognition from shadow analysis. We describe compensation steps to address shadow variation with conditions of observation (sun position, etc). We define measures of shape variation, such as horizontal stripes on the silhouette, their length change in time determines frequency components (here spherical harmonics) for each gait cycle, which are used for classification by a k-nearest neighbor classifier. A correct classification rate (CCR) of 95 % was obtained. A degradation of CCR from 95 % to 75 % was observed when reduced spatial and temporal resolution from 1cm to 2cm, and from 30fps to 15fps.

Original languageEnglish
Title of host publication2010 IEEE International Conference on Image Processing, ICIP 2010 - Proceedings
Number of pages4
Publication statusPublished - Dec 1 2010
Event2010 17th IEEE International Conference on Image Processing, ICIP 2010 - Hong Kong, Hong Kong
Duration: Sep 26 2010Sep 29 2010

Publication series

NameProceedings - International Conference on Image Processing, ICIP
ISSN (Print)1522-4880


Other2010 17th IEEE International Conference on Image Processing, ICIP 2010
Country/TerritoryHong Kong
CityHong Kong

All Science Journal Classification (ASJC) codes

  • Software
  • Computer Vision and Pattern Recognition
  • Signal Processing


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