[judge2020]

We might also see DL image upscaling used. Obtain similar-looking pictures (at 128x128 or even smaller), downscale to 26x26, train DL to do 128x128 or larger upscaling using the original picture as training data. Assuming most content in the actual DB is similar, you can probably obtain plausible results. A similar technique is used by Peacemaker Filmworks to upscale 4k to 8k: https://youtu.be/umyglbDr4IE?t=257

[nomel]

That will be an incredibly questionable dataset used to train it. At that point, there would probably be no need to upscale these images. Just downscale then use this questionable DL to re-upscale any image.