A background subtraction approach based on complex wavelet transforms in EDXRF

Subtracting the background accurately is one of the most important issues in energy-dispersive X-ray fluorescence (EDXRF) spectra processing. This paper presents a novel approach to perform background subtraction based on dual-tree complex wavelet transform. Compared with real wavelet transform, the proposed method has some attractive properties, including a smooth, nonoscillating, and nearly shift-invariant magnitude with a simple near-linear phase encoding of signal shifts. Therefore, it outperforms real wavelet transform to decompose background into low-frequency components. The effectiveness of the proposed approach is demonstrated via two simulated spectra with different kinds of backgrounds and one measured spectrum from an energy-dispersive X-ray spectrometer. Both simulated and experimental results prove that the proposed approach can subtract background in EDXRF spectra effectively. Copyright (c) 2014 John Wiley & Sons, Ltd.