Holographic particle sizing by using absolute values of the wavelet transform

A new method for sizing particle from in-line Fraunhofer holograms by using absolute values of the wavelet transform is proposed. The method gives zero-crossing points of an envelope function of the hologram which are determined by the particle size. Since the resultant zero-crossing points are functions of the dilation parameter, the frequencies of the fringes at the zero-crossing points are measured. The particle size can be finally calculated from the relationship between the frequencies with the positions of the zero-crossing points. The experimental results agree well with the theory.