Microscopy Primer
Light and Color
Microscope Basics
Special Techniques
Digital Imaging
Confocal Microscopy
Live-Cell Imaging
Photomicrography
Microscopy Museum
Virtual Microscopy
Fluorescence
Web Resources
License Info
Image Use
Custom Photos
Partners
Site Info
Contact Us
Publications
Home

The Galleries:

Photo Gallery
Silicon Zoo
Pharmaceuticals
Chip Shots
Phytochemicals
DNA Gallery
Microscapes
Vitamins
Amino Acids
Birthstones
Religion Collection
Pesticides
BeerShots
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

Iterative Morphological Operations

The basic morphological functions are erosion, the removal of pixels from the periphery of a feature, or dilation, the adding of pixels to that periphery. Classical erosion removes any pixel that has a background neighbor (any of the eight neighbors that share an edge or corner). Conversely, classical dilation adds any pixel that touches a pixel in the feature. Of course, both of these operations change the size of features or structures and so they are most often used together. An opening is an erosion followed by a dilation, while a closing is a dilation followed by an erosion. These operations can smooth irregular borders, and fill in or remove isolated pixel noise and fine lines.

This interactive tutorial illustrates the use of iterative morphological operations on a binary image. In the tutorial, each function can be applied multiple times to add or remove more pixels. An opening of M iterations consists of M steps of erosion, followed by M steps of dilation, and vice versa.

The tutorial initializes with a randomly selected specimen appearing in the Specimen Image window. The Choose A Specimen pull-down menu provides a selection of thresholded binary images, in addition to the initial randomly chosen one. The Operation buttons select Erosion, Dilation, Opening or Closing. The Iterations slider controls the number of times the selected operation is performed. The Neighborhood Threshold slider controls the conditional test based on the number of neighboring pixels that must be of the opposite color (black or white) for the pixel to change state. Setting this to 0 corresponds to classical morphological operations. The result of the selected operation and settings is shown in the Processed Image at the right.

Contributing Authors

John C. Russ - Materials Science and Engineering Dept., North Carolina State University, Raleigh, North Carolina, 27695.

Matthew Parry-Hill, and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.


BACK TO INTRODUCTION TO DIGITAL IMAGE PROCESSING AND ANALYSIS

BACK TO MICROSCOPY PRIMER HOME

Questions or comments? Send us an email.
© 1998-2009 by Michael W. Davidson, John Russ, Olympus America Inc., and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Tuesday, Sep 11, 2018 at 02:25 PM
Access Count Since July 20, 2006: 8353
For more information on microscope manufacturers,
use the buttons below to navigate to their websites: