Moving shadow detection based on stationary wavelet transform and Zernike moments
The presence of shadows degrades the performance of many computer vision and video surveillance applications, as objects can be incorrectly classified. The article proposes a method for detecting moving shadows using stationary wavelet transform (SWT) and Zernike moments (ZM) based on an automatic threshold determined by the wavelet coefficients. The multi-resolution and shift invariance properties of the SWT make it suitable for change detection and feature extraction. To reduce the redundant wavelet coefficients, ZM are applied. The novelty of the proposed method is the determination of the variant statistical threshold – ‘skewness’, without the requirement of any supervised learning or manual calibration. The experimental results prove that the proposed threshold performs well to show a better variation between the objects and shadows in various environments.