Elements of Morphology

Types of Morphological Operations

The most basic morphological operations are dilation and erosion. You can combine dilation and erosion for more specialized operations.

Morphological Reconstruction

Morphological reconstruction is used to extract marked objects from an image without changing the object size or shape.

Structuring Elements

A structuring element defines the neighborhood used to process each pixel. A structuring element influences the size and shape of objects to process in the image.

Border Padding for Morphology

Morphological dilation and erosion pad the image border in different ways to avoid border effects.

Pixel Connectivity

Connectivity determines whether a center pixel and adjacent pixels belong to the same object.

Lookup Table Operations

A lookup table is a vector in which each element represents the different permutations of pixels in a neighborhood. Lookup tables are useful for custom erosion and dilation operations.

Applications of Morphology

Dilate an Image to Enlarge a Shape

Dilation adds pixels to boundary of an object. Dilation makes objects more visible and fills in small holes in the object.

Erode an Image To Remove Thin Lines

Erosion removes pixels from the boundary of an object. Erosion removes islands and small objects so that only substantive objects remain.

Use Morphological Opening to Extract Large Image Features

You can use morphological opening to remove small objects from an image while preserving the shape and size of larger objects in the image.

Flood-Fill Operations

A flood fill operation assigns a uniform pixel value to connected pixels, stopping at object boundaries.