MDGrain vs Dfttest

[may24]

Hi all,

MDGrain and Dfttest are two popular and commonly used methods to denoise some video streams.

But what are they doing in detail ?
And what would be the advantage of one over the other ... and when to choose MDGrain over Dfttest or vice versa.

[feisty2]

MDegrain does a weighted average between frames (weights calculated from the SAD of the reference block and the current block)
DFTTest transforms the vid from time domain to frequency domain via DFT, and applies a wiener filter in frequency domain and then converts the signal back to time domain

MDegrain = good stuff to high frequencies like edges, "strong" details, etc
DFTTest = good stuff to low frequencies like flat areas, "weak" details, etc