Morphological Image Processing

Morphological Image Processing #

Morphological image processing is a technique for analyzing and manipulating shapes in images. It uses transformations based on a defined structure, called a structuring element (SE), to extract geometric and topological information from an image.

Fundamental Operations #

  • Dilation: Expands the boundaries of objects by adding pixels.
  • Erosion: Shrinks objects by removing pixels from the boundaries.
  • Opening: Removes small noise while preserving the shape of larger objects.
  • Closing: Fills small holes and gaps in objects.
  • Hit-or-Miss: Detects specific patterns in the image by matching structuring elements.

Structuring Elements #

Structuring elements define the shape and size used for morphological operations. Common examples include:

  • Squares
  • Circles (disks)
  • Crosses
  • Diamonds

The design of the structuring element is crucial for the success of the operations.

Logical Equivalents in Morphology #

Morphological operations are closely related to set theory and logic:

  • Intersection corresponds to logical AND.
  • Union corresponds to logical OR.
  • Complement corresponds to logical NOT.
  • Difference (A - B) corresponds to A AND NOT B.

Applications #

  • Boundary Extraction: Detects object boundaries.
  • Region Filling: Fills in holes within objects.
  • Thinning and Thickening: Refines or emphasizes object boundaries.
  • Skeletonization: Reduces objects to their basic structure or skeleton.

Benefits of Morphological Processing #

  • Cleans up noisy binary images.
  • Analyzes geometric shapes and their relationships.
  • Prepares images for advanced tasks such as segmentation and classification.