Removing multi-frame Gaussian noise by combining patch-based filters with optical flow
Kireeti Bodduna, Joachim Weickert · Journal of Electronic Imaging · 2021
Patch-based approaches such as 3D block matching and non-local Bayes are widely accepted filters for removing Gaussian noise from single-frame images. We propose three extensions for these filters when there exist multiple frames of the same scene. The first of them employs reference patches on every frame instead of a commonly used single-reference frame method, thus utilizing the complete available information. The remaining two techniques use a separable spatiotemporal filter to reduce interactions between dissimilar regions, hence mitigating artifacts. In order to deal with non-registered datasets, we combine all our extensions with robust optical flow computation. Two of our proposed multi-frame filters outperform existing extensions on most occasions by a significant margin while also being competitive with a state-of-the-art neural network-based technique. Moreover, one of these two strategies is the fastest among all due to its separable design.