Function binary_opening 

pub fn binary_opening(
    mask: &ArrayRef3<bool>,
    kernel: &ArrayRef3<bool>,
    iterations: usize,
) -> Mask

Binary opening of a 3D binary image.

The opening of an input image by a structuring element is the dilation of the erosion of the image by the structuring element.

Unlike other libraries, the border values of the:

• dilation is always false, to avoid dilating the borders
• erosion is always true, to avoid border effects

• mask - Binary image to be opened.
• kernel - Structuring element used for the opening.
• iterations - The erosion step of the opening, then the dilation step are each repeated iterations times.