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

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