Mitigating ringing artifacts in diffraction calculations using average subtractions

Abstract

Fourier transform-based diffraction calculations are essential for computational optics. However, the diffraction calculations can be corrupted by the introduction of strong ringing artifacts due to the introduction of zero-padding to avoid circular convolution or to control the sampling intervals. We propose a simple de-ringing method using average subtractions for application to on-axis and off-axis diffraction calculations. To verify the effectiveness of the proposed method, we compared the diffracted fields obtained using zero-padding, a flat-top window method, a mirror expansion method, and the whole and border average subtractions proposed. Furthermore, we confirmed the effectiveness of the proposed method for hologram calculations using double phase encoding and image reconstructions of inline digital holography.

Suppression of ringing artifacts in diffraction calculations

“…The proposed method does not require additional diffraction calculation and memory usage. In addition, this study compares the proposed method with the average subtraction 9 and the aperture division method. 10…”

Compressive digital holography and Gibbs ringing

“…Shimobaba et al note that strong ringing artefacts can arise when zero padding is used in Fourier transform-based diffraction calculations,. 18 Two main requirements need to be met for the CS theory to apply. 8 The first is that when the sparsifying operator transforms the object from its spatial representation to another domain, the object has a sparse representation in that domain.…”