Function laplacian_unwrap 

pub fn laplacian_unwrap(
    phase: &[f64],
    mask: &[u8],
    grid: &Grid,
    solver: LaplacianSolver,
) -> Vec<f64>

Laplacian phase unwrapping, without background field removal.

Solves the Poisson equation over the whole array with the chosen LaplacianSolver (see the module docs for both). Nothing is masked out of the input, so field sources anywhere in the FOV are retained and the harmonic (background) component survives: the result is an unwrapped total field, suitable for a subsequent background-removal stage. (With LaplacianSolver::Fft the total field carries a harmonic error from the zero padding wherever the phase at the array edge is not zero; the local field is unaffected.)

Because the whole array participates, this is sensitive to phase quality outside the ROI. STI Suite-based pipelines zero the phase outside the brain first (mask · φ), which run_field_mapping does on its multi-echo Laplacian path; otherwise, where the phase outside the object is noise, or wraps faster than one radian per voxel, prefer ROMEO (super::romeo::unwrap_romeo).

Arguments

• phase - Wrapped phase (nx * ny * nz)
• mask - Binary mask (nx * ny * nz); applied to the output only
• grid - Volume grid (dimensions and voxel sizes)
• solver - LaplacianSolver::Dct (default) or LaplacianSolver::Fft

Returns

Unwrapped phase, zero outside mask.

References

Ghiglia & Romero (1994) for Dct; Schofield & Zhu (2003) for Fft. See the module docs.