Region Growing

Region growing approach is the opposite of the split and merge approach:

Region growing methods often give very good segmentations that correspond well to the observed edges.
Fig. 37 Example of region growing
However starting with a particular seed pixel and letting this region grow completely before trying other seeds biases the segmentation in favour of the regions which are segmented first.
This can have severalundesirable effects:
To counter the above problems, simultaneous region growing techniques have been developed.