Module nltv 

Nonlinear Total Variation (NLTV) regularized dipole inversion

NLTV extends standard TV by using iteratively reweighted minimization, which produces sharper edges and better preserves fine details.

The method solves: min_x ||Dx - f||₂² + λ Σ w_i |∇x|_i

where weights w_i are iteratively updated based on the current solution.

Reference: Kames, C., Wiggermann, V., Rauscher, A. (2018). “Rapid two-step dipole inversion for susceptibility mapping with sparsity priors.” NeuroImage, 167:276-283. https://doi.org/10.1016/j.neuroimage.2017.11.018

Reference implementation: https://github.com/kamesy/QSM.jl

Structs

NltvParams

NLTV algorithm parameters

Functions

nltv

NLTV dipole inversion using iteratively reweighted ADMM

nltv_default

NLTV with default parameters (matches QSM.jl nltv.jl defaults)

nltv_with_progress

NLTV with progress callback

weighted_shrink 🔒

Weighted soft thresholding operator