The algorithm starts with a set of seed points, each corresponding to an individual region.
The seed points are then compared to their neighbours based on a similarity criterion.
The neighbours of a pixel are computed either by 4-connectivity or 8-connectivity.
In 4-connectivity,
the neighbours are the pixels that are connected horizontally and vertically,
while in 8-connectivity,
the neighbouring pixels are the ones that are connected horizontally,
vertically, and diagonally.
The simplest similarity criteria generally used is obtained by calculating the difference between the intensity value of the image pixel and the corresponding region mean.
If the difference is less than a specified threshold,
then the pixel belongs to that region and is subsequently labelled.
Otherwise the pixel is not labelled and skipped.
The algorithm for implementing the seeded region growing algorithm is as follows: