> resharpen an image that had been passed through a blur filter This is trivial if you know what filter was used and it’s possible even if you don’t know the f

> resharpen an image that had been passed through a blur filter This is trivial if you know what filter was used and it’s possible even if you don’t know the filter: https://en.m.wikipedia.org/wiki/Blind_deconvolution https://en.m.wikipedia.org/wiki/Blind_deconvolution Note that when you blur an image in software, information is only lost when you round each channel to the nearest u8. Each of the NxN output pixels is a linear combination of the NxN input pixels. There are only N^2 equations with N^2 unknown variables.