2D transform-domain Fourier filters for eliminating microsaccade noise in en face optical coherence tomography angiography

摘要

Microsaccade noise is fast-scan-directional bright short lines in en face optical coherence tomography angiographyimages. We propose to use 2D Fourier filters in different transform domains including Fourier, wavelet, andnonsubsampled contourlet domains to eliminate this kind of noise. We used image entropy and vessel density as themetrics to evaluate their performance on noise elimination, we found that filtering after the nonsubsampled contourlettransform (NSCT) was the best choice among these approaches. For vessel preservation, the wavelet-domain filteringhas the advantage of keeping signal-to-noise ratio while the NSCT filtering can preserve structure similarity to the mostextent.