OBJECT AND SHADOW TRACKING

J. Stauder, contact: J. Stauder, H. Nicolas

Goal

For MPEG-4 applications like video post production, remote data base access or surveillance, moving objects need to be segmented automatically in a video sequence.

Problem

In presence of directed light, cast shadows may occur. Since cast shadows move together with the objects, they are likely to be detected as moving objects.

Approach

To scope with the shadow problem, a method is proposed that detects and tracks moving cast shadows explicitly. Cast shadows are assumed to be on a dominant background. First, temporal luminance changes caused by moving cast shadows are identified by typical shadow characteristics [VLBV'97]. Then, these changes are temporally integrated resulting to regions of entire moving cast shadows . These detected cast shadows are given to an object segmentation algorithm to avoid shadows being detected as objects [Stau99a][WIAMIS'99].

Experimental Results

The following result demos are available:

References

[Stau99a]

J. Stauder, R. Mech, J. Ostermann: "Detection of Moving Cast Shadows for Object Segmentation", IEEE Trans. on Multi Media, Volume 1, No.1, March 1999, pp. 65-76 (downloadable: draft version pdf and ps)

[WIAMIS'99]

J. Stauder, R. Mech: "Detection and Tracking of Moving Cast Shadows", COST211 Workshop on Image Analysis for Multimedia Interactive Services WIAMIS'99, Berlin, Germany, 31.5.-1.6.1999. (pdf)

[VLBV'97]

J. Stauder: "Segmentation of Moving Objects in Presence of Moving Shadows" International Workshop on Very Low Bit-rate Video Coding (VLBV), Linkoeping, Sweden, 28-30 July 1997, pp. 41-44

[COST]

http://www.teltec.dcu.ie/cost211