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This is not a general-moire-removal technique. It's basically a band-stop filter that removes those frequencies from an image that correspond to the size of hal
by Sharlin 5y ago
This is not a general-moire-removal technique. It's basically a band-stop filter that removes those frequencies from an image that correspond to the size of halftone dots both horizontally and vertically. Nifty use case for FFT though, would probably make a good homework assignment on an undergrad DSP course.
- carlob 5y ago> removes those frequencies from an image that correspond to the size of halftone dots both horizontally and vertically And all the harmonics that make out the circle shape. I'm pretty sure that making the circle repeat horizontally and vertically is some kind of convolution product and that has some nifty properties under Fourier transform.