Function open

pub fn open(image: &GrayImage, norm: Norm, k: u8) -> GrayImage

Erosion followed by dilation.

See the erode and dilate documentation for definitions of dilation and erosion.

Examples

use imageproc::morphology::open;
use imageproc::distance_transform::Norm;

// Isolated regions of foreground pixels are removed.
let cross = gray_image!(
      0,   0,   0,   0,   0;
      0,   0, 255,   0,   0;
      0, 255, 255, 255,   0;
      0,   0, 255,   0,   0;
      0,   0,   0,   0,   0
);

let opened_cross = gray_image!(
      0,   0,   0,   0,   0;
      0,   0,   0,   0,   0;
      0,   0,   0,   0,   0;
      0,   0,   0,   0,   0;
      0,   0,   0,   0,   0
);

assert_pixels_eq!(
    open(&cross, Norm::LInf, 1),
    opened_cross
);

// Large blocks survive unchanged.
let blob = gray_image!(
      0,   0,   0,   0,   0;
      0, 255, 255, 255,   0;
      0, 255, 255, 255,   0;
      0, 255, 255, 255,   0;
      0,   0,   0,   0,   0
);

assert_pixels_eq!(
    open(&blob, Norm::LInf, 1),
    blob
);