In order to overcome the problems of poor universality and sensitivity of light change in the existing shadow detection methods based on optical properties, a moving shadow detection method based on space location feature is introduced. A calibrated binocular stereo camera is used to capture stereo background images at the same time. The position relationships between matching points from the pair of background images is calculated off-line. The cast shadows adhere to the background surface, and the matching points of that shadow have the same position relationships with that of the background stereo images, so the cast shadows can be removed by comparing the level of similarities of pixel values between the left and right images on the position of matching points in the background. Prior knowledge about neither the environment characteristics nor the lighting conditions is required in the proposed approach, and all kinds of complicated lighting conditions will not affect the detection precision. Experimental results demonstrate that this approach can effectively detect moving shadows.
Received: 30 May 2012
Published: 15 September 2012