In this example of blurring a small vertical blurring mask  f  is convolved with the original signal X to achieve  a blurred image f*X. The steps to unblur or restore the image are:

Original Blurred Image

Magnitude of  DFT of Blurred Image

Magnitude of Optical Transfer Function 
OTF = DFT of blurring mask

Magnitude of Pseudo Inverse

Magnitude of Pseudo Inverse times OTF

Pseudo- inverse times DFT 
of Blurred Image

Restored Image

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