Region Growing
Region growing is an image segmentation technique .
procedure
In this process, homogeneous picture elements are merged into regions. First, the image is divided into initial cells (1 × 1, 2 × 2 or 4 × 4 pixels ). Beginning with the selection of an initial cell as the starting region, this is then compared with the neighboring cells on the basis of a criterion (e.g. the difference between the gray value and that of the neighboring cell). If the criterion is met, the neighboring cell is added to the region. This is repeated recursively, that is, the neighboring cells of the newly added cells are also examined. If no more neighbors can be added, a region has been found.
The process can be repeated for other cells that do not belong to the region until all pixels have been assigned regions. However, depending on the selected criterion, this can lead to overlapping regions.
The method is prone to "leakage", which means that actually separate regions are recorded as one region by small "pixel bridges".