Segmentation of the background of 3D images based on classes
outside(img, what, blobsize = 1)is a 3d array representing an image.
is an integer of the class of the background.
is an integer, representing the minimal diameter for bridges from the outside. E.g., a blobsize=3 allows for holes of size 2*(blobsize-1)=4 in the edge of the object.
A binary 3d array: 1 outside the object, 0 inside the object