Elongatedness

In image processing, elongatedness for a region is the ratio between the length and width of the minimum bounding rectangle of the region. It is considered a feature of the region. It can be evaluated as the ratio between the area of the region to its thickness squared:

${\displaystyle elongatedness={\frac {length}{width))={\frac {area}{(2d)^{2))))$.

where the maximum thickness, ${\displaystyle d}$, of a holeless region is given by the number of times the region can be eroded before disappearing.^[1]