Function connected_components 

pub fn connected_components(
    image: &[f32],
    width: usize,
    height: usize,
) -> Result<Vec<u32>, ImageError>

Connected component labeling using union-find (4-connectivity).

Input: binary image (0.0 = background, nonzero = foreground). Output: label array where each connected region has a unique ID (0 = background).

Errors

Returns error if buffer length doesn’t match dimensions.