Add Spectral Reconstructor

[Vestaia]

Spectral Reconstructor

Anti-chatter filter based on separation of signal and noise using decomposition into a semi-spectral latent space, providing substantially better noise rejection than conventional filters without the shape distortion (smoothing) of conventional filters.
An integrated resampled + extrapolator is included to handle input jitter (USB quantization, scheduling misses, tablet stalls, etc...). This is chosen over chaining the existing "temporal resampler" because the anti-chatter filter requires tuning to input cadence.

This filter is based on a custom designed latent space with affine + semi-spectral modes. Noise and typical pen movement occupy distinctly different modes in this space -- pen movement occupy only the lowest eigenvalue modes while noise has near uniform occupation across all modes. Filtering is done by only performing reconstruction using a user-defined number of lowest energy modes (set by strength parameter).

Validation

• Tested successfully in OpenTabletDriver 0.6.7. on both Windows and Linux
• Release build targets .NET 8 and produces a single plugin DLL.
• Measured 10.77dB noise rejection at stock settings (4 sample latency).
• Licensed under SUL-1.0 (Free use, distribution, and modification for any non-commercial purpose).

Release

• Plugin version: 1.1.5.0
• Minimum OpenTabletDriver version: 0.6.7.0
• Release ZIP contains Spectral.Reconstructor.dll at its top level.
• ZIP SHA-256: ea9ddccfaf8b83c7d3f19ed3f1c09eb7fcd99ae72b4c4b71b38d768b2706b148
• https://github.com/Vestaia/Spectral-Reconstructor