Wavelet-based image denoising in (digital) particle image velocimetry

Mallat algorithm, which analyzes the evolution of the wavelet transform max ima across scales based on wavelet transform, is applied in image denoising in particle image velocimetry (PIV) in this paper. An improved interrogati on method for PIV images based on cross-correlation with discrete window of fset, which makes use of a translation of the second interrogation window a nd rebuilds it considering rotation and shear is also presented. The displa cement extracted from PTV images is predicted and corrected by means of an iterative procedure. In addition, the displacement vectors are validated at each intermediate of the iteration process. The method of image denoising in PIV based on wavelet transform is compared with averaging filter, Wiener filter and median filter by interrogation of synthetic and real PIV images and the results are discussed. (C) 2001 Elsevier Science B.V. All rights r eserved.