Denoising by spatial correlation thresholding

Abstract

This paper presents a spatial-correlation thresholding scheme for noise reduction by wavelet transform. Observing that edge structures are of high magnitude across wavelet scales but noise decays rapidly, we multiply two adjacent wavelet scales to form a spatial-correlation function to enhance significant structures and dilute noise. Dissimilar to the traditional thresholding schemes that apply threshold to the wavelet coefficients, the proposed scheme applies threshold directly to the scale correlation. A robust threshold is presented and experiments show that the proposed scheme outperforms the traditional thresholding methods.