[Neo] FFT3D / DFTTest

[MeteorRain]

This thread serves Neo-FFT3D and Neo-FFTTest.

Neo filters family is not to be confused with AviSynth-Neo. Neo filters family is not affiliated in any way with AviSynth-Neo.

[Neo] FFT3D → GitHub

FFT3DFilter is a 3D Frequency Domain filter - strong denoiser and moderate sharpener. It was originally written by Alexander G. Balakhnin aka Fizick, and later modified by martin53 for AviSynth 2.6 and later modified by Ferenc Pintér aka pinterf for further improvement, high bit depth, and more. Kudos to them for creating and improving this fantastic tool.

Difference compared to pinterf/FFT3DFilter

• Dual interface, supporting AviSynth+ and VapourSynth
• Removed YUY2
• Removed multiplane options, added y, u, v options for plane control
• Removed existing 3DNow and SSE code
• Fixed an incorrect coefficient in Apply2D
• Added SSE, AVX and AVX512 routine
• Added multi-threading, both internal and AVS-MT prefetch

Result bit-identicalness

• Neo-FFT3D C - FFT3DFilter C: identical except for a few situations
• Except: bt=2 and sharpen and dehalo where the incorrect coefficient is fixed
• Except: bt=4, 5 where the floating point numbers are added in different way ( (fp2r + fpr) + (fcr + fnr) in Neo-FFT3D, (fp2r + fpr + fcr + fnr) in FFT3DFilter ) resulting rounding error
• Except: bt=0 and pfactor > 0 causing crash, need your investigation and fixes
  ===== ===== ===== =====
• Neo-FFT3D SSE - C: identical
• Neo-FFT3D AVX - C: identical
• Neo-FFT3D AVX512 - C: theoretically identical

[Neo] DFTTest → GitHub

DFTTest is a 2D/3D Frequency Domain denoiser. It was originally written by tritical, and later modified by Ferenc Pintér aka pinterf for further improvement, high bit depth, and more. VapourSynth-DFTTest was ported to VapourSynth interface by HolyWu with further clean ups and efficient SSE2 and AVX2 SIMD routines. Kudos to them for creating and improving this fantastic tool.

Difference compared to pinterf/dfttest

• Dual interface, supporting AviSynth+ and VapourSynth
• Parameter names and opt levels follow VapourSynth-DFTTest
• Removed Y, U, V options, added y, u, v options for plane control
• Removed hacked 16 bit I/O
• Replaced internal multi-threading with C++ Parallel STL, removed Windows specific APIs
• Improved precision of floating point reciprocal using Newton Raphson method
• sigma/sigma2/sbsize/sosize/tbsize etc. has different default value

Difference compared to HomeOfVapourSynthEvolution/VapourSynth-DFTTest

• Dual interface, supporting AviSynth+ and VapourSynth
• Added dither option from AVS counterpart
• Added internal multi-threading
• Replaced division by Newton Raphson method reciprocal in SSE2
• Replaced reciprocal approximation by Newton Raphson method in AVX2

Result bit-identicalness

• Neo-DFTTest C - (AVS)DFTTest C: identical except when nlocation is provided, due to order of floating point multiplication
  Neo-DFTTest: data = data * (scale * (wscale2 / wscale) * alpha)
  (AVS)DFTTest: data = data * scale * (wscale2 / wscale) * alpha
• Neo-DFTTest C - (VS)DFTTest C: identical
  ===== ===== ===== =====
• Neo-DFTTest SSE - C: identical except when dither > 2, due to rounding errors in dithering
• Neo-DFTTest AVX - C: identical except when dither > 2, due to rounding errors in dithering