A spectral optical flow method for determining velocities from digital imagery
This is an incremental improvement for solar physics researchers, offering a method that simplifies velocity extraction from solar imagery.
The authors tackled the problem of determining surface flows from solar images by developing a spectral optical flow method, which provides accurate velocity estimates comparable to established methods without requiring image preprocessing.
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.