By Nyquist Theorem, we know that if we upsample twice the frequency, we could get the original one back after downsampling it. Just curious, is there any way that upsampling after downsampling will actually give you the original one back?

keenan

@siliangl The Nyquist theorem depends on more than just the sampling rate: it also uses the so-called sinc filter to perform a reconstruction. I am not aware of an analogue for the sinc filter for irregularly sampled surface geometry (though it's possible someone has cooked up something analogous...)

By Nyquist Theorem, we know that if we upsample twice the frequency, we could get the original one back after downsampling it. Just curious, is there any way that upsampling after downsampling will actually give you the original one back?

@siliangl The Nyquist theorem depends on more than just the sampling rate: it also uses the so-called

sincfilter to perform a reconstruction. I am not aware of an analogue for the sinc filter for irregularly sampled surface geometry (though it's possible someone has cooked up something analogous...)