In the last post, many moons ago, I introduced the 2-D FFT and discussed the magnitude and phase components of the spatial Fourier domain. In the next few posts, I would like to describe a concrete application of the 2-D FFT, namely blurring. Blurring and deblurring are useful image processing techniques that can be used in a variety of fields. I will explain what blur is mathematically and how it is performed artificially. In future posts, I’ll go into more depth about what happens in the spatial domain, different types of blur, and some current deblurring technology.