Function distance_transform_edt_u8_into 

pub fn distance_transform_edt_u8_into(
    input: &[u8],
    width: usize,
    height: usize,
    output: &mut [f32],
    workspace: &mut DistanceTransformWorkspace,
) -> VisionResult<()>

Computes a unit-spacing exact distance transform from a packed u8 mask.

Zero is background and every non-zero value is foreground, so common 0/255 image masks need no normalization copy. input and output must both have exactly width * height elements.