Function vsharp 

pub fn vsharp(
    field: &[f64],
    mask: &[u8],
    grid: &Grid,
    params: &VsharpParams,
    progress: impl FnMut(usize, usize),
) -> (Vec<f64>, Vec<u8>)

V-SHARP background field removal

Uses multiple SMV kernel radii, starting from largest and decreasing. At each voxel, uses the smallest radius that doesn’t touch the boundary.

Arguments

• field - Unwrapped total field (nx * ny * nz)
• mask - Binary mask (nx * ny * nz), 1 = inside ROI
• grid - Volume dimensions and voxel sizes
• params - V-SHARP parameters (threshold, min/max radius in mm)
• progress - Progress callback (radius_index, total_radii)

Returns

(local_field, eroded_mask)