A spectral optical flow method for determining velocities from digital imagery

TL;DR

This paper introduces a spectral optical flow method called opflow3d for accurately determining surface velocities from solar images, demonstrating its effectiveness across various datasets and comparison with existing methods.

Contribution

The paper presents the opflow3d technique, a new optical flow method that requires no preprocessing and provides accurate velocity estimates from solar imagery.

Findings

Accurately extracts velocities from perfect test data.

Produces results consistent with other methods on global scales.

Provides comparable results to established methods on high-resolution data.

Abstract

We present a method for determining surface flows from solar images based upon optical flow techniques. We apply the method to sets of images obtained by a variety of solar imagers to assess its performance. The {\tt opflow3d} procedure is shown to extract accurate velocity estimates when provided perfect test data and quickly generates results consistent with completely distinct methods when applied on global scales. We also validate it in detail by comparing it to an established method when applied to high-resolution datasets and find that it provides comparable results without the need to tune, filter or otherwise preprocess the images before its application.