Function erode 

pub fn erode(
    image: &[f32],
    width: usize,
    height: usize,
    se: &[f32],
    se_w: usize,
    se_h: usize,
) -> Result<Vec<f32>, ImageError>

Erode: output pixel = min of neighborhood defined by structuring element.

Errors

Returns error if dimensions don’t match or SE is invalid.