Pairs of original Hα filtergrams (left) as provided to the model and the resulting reconstruction (right). Top panel: samples of the high-quality distribution, bottom panel: samples from the low-quality domain. (a) Illustration of the feature-based image translation. The reconstructed filament can be clearly identified, but shows differences in appearance from the original. (b) Example of the image-quality decrease of a high-quality image due to strong compression. (c) For low-quality images, the unknown features result in artifacts in the reconstruction. (d) Global atmospheric effects show strong differences in the reconstructed image.