Dilation is a morphological operation used to enhance the features of an image. Dilation as a function requires two inputs, an image to be dilated, and a two dimensional structuring element. Dilation has many applications, but is most commonly used to exaggerate features in an image that would otherwise be missed.

Definition Edit

Dilation for binary images is defined as follows:

Let X be the set of coordinates corresponding to the input binary image, and that K is the set of coordinates for the structuring element.

Let Kx denote the translation of K so that its origin is at x.

Then the dilation of X by K is simply the set of all points x such that the intersection of Kx with X is non-empty.

Usage Edit


A binary image of some blobs on a microscope slide


The image above, dilated with a full 3x3 kernel

Dilation is frequently used to enhance the structure of an image, by either exaggerating features in the foreground, or conversely, obscuring features in the background.