BWDIF for VS

[richardpl]

What is QTGMC actually? NNEDI3 or EEDI3 or EEDI2 or something completely else?

[Jukus]

Originally Posted by richardpl

What is QTGMC actually? NNEDI3 or EEDI3 or EEDI2 or something completely else?

QTGMC is a whole complex of filters (noise reduction, anti-aliasing and others).
The default is NNEDI3, but can choose another plugin.

[LoRd_MuldeR]

QTGM evolved from TempGaussMC, originally created by Didée. It is "a motion-compensated bob deinterlacer, based on temporal gaussian blurring".

It is a highly complex Avisynth script, using all sorts of plug-ins. Most notably but not limited to MVTools2 (motion compensation), MaskTools v2 (masking), NNEDI3 (interpolation) as well as RemoveGrain (denoising).

The core algorithm is this:

• Bob the source clip. Temporally smooth the bob to remove shimmer then analyse its motion
• More accurately interpolate the source clip (e.g. NNEDI3). Use the motion analysis from previous step to temporally smooth this interpolate with motion compensation. This removes shimmer whilst retaining detail. Resharpen the result to counteract any blurring
• A final light temporal smooth to clean the result

Stages 0 & 1 use a binomial smooth (similar to a Gaussian) to remove deinterlacing shimmer. Stage 2 uses a simple linear smoothing.

NNEDI/2/3 and EEDI2/3 "only" are interpolators.

Simply put, they take an image with only half the lines (one field) and interpolate the missing lines. That alone would not make good deinterlacer, but it is an important "ingredient" for implementing stuff like QTGMC.

(Well, I think NEEDI3 alone would make a decent half-rate deinterlacer, but you do not want to use "pure" NEEDI3 for bobbing)