What exactly is connectivity between pixels in an image?

Pixels are connected if their edges or corners touch. Two adjoining pixels are part of the same object if they are both on and are connected along the horizontal, vertical, or diagonal direction. Current pixel is shown in gray. Pixels are connected if their faces touch.

1. What is adjacency between pixels?
2. What do you mean by 8 connected Neighbours of a pixel?
3. What is 4 connectivity?
4. What is 4-connected and 8 connected in image processing?

What is adjacency between pixels?

Adjacency: Two pixels are adjacent if they are neighbors and their intensity level 'V' satisfy some specific criteria of similarity. In binary images, 2 pixels are adjacent if they are neighbors & have some intensity values either 0 or 1. In gray scale, image contains more gray level values in range 0 to 255.

What do you mean by 8 connected Neighbours of a pixel?

Definition of an 8-neighbor:

A pixel, Q, is an 8-neighbor (or simply a neighbor) of a given pixel, P, if Q and P either share an edge or a vertex. The 8-neighbors of a given pixel P make up the Moore neighborhood of that pixel.

What is 4 connectivity?

Definition of a 4-connected component :

A set of black pixels, P, is a 4-connected component if for every pair of pixels p_i and p_j in P, there exists a sequence of pixels p_i, ..., p_j such that: a) all pixels in the sequence are in the set P i.e. are black, and.

What is 4-connected and 8 connected in image processing?

If the foreground is 4-connected, the image has one background object, and all the pixels are set to 0 . However, if the foreground is 8-connected, the foreground makes a closed loop and the image has two separate background objects: the pixels in the loop and the pixels outside the loop.