Comment by gus_massa
3 years ago
Can it be just deconvolution? https://en.wikipedia.org/wiki/Deconvolution
The Gaussian blur they applied is theoretically reversible in a continuous function and infinite precision. In a discrete function (like a image in the computer) and only a few dozens of bits it's not 100% reversible, but it can be partially undone and get a sharper image (that is not as sharp as the initial image).
No. The author downsampled the image to 170x170 pixels and clipped the white levels so that details were turned to uniform white.
I guess one way to tell whether the image is processed locally is by disabling every connection, and seeing if the pics still look good.
But there still might be advanced machine learning models, rather than simple filters.