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

Texture Directionality

Texture or structure in an image may also have directionality. This can be detected as a property and used to label regions by applying the same Sobel brightness gradient vector introduced above as an edge delineation tool. The magnitude of the vector was used to outline steps and edges. The orientation angle of the vector can be used to characterize local orientation. The angle from 0 to 180 or from 0 to 360 degrees is generally scaled to the 0..255 brightness range of the display, or shown as a color. For the directions and cloth images this shows that the visually distinct regions of the image can be separated by the procedure. For the collagen image, the histogram is a quantitative measure of the preferred orientation of the fibers. This interactive Java tutorial illustrates the use of the angle of the local brightness gradient vector to convert textural orientation differences to brightness differences for regions in an image.

Interactive Java Tutorial
ATTENTION
Our servers have detected that your web browser does not have the Java Virtual Machine installed or it is not functioning properly. Please install this software in order to view our interactive Java tutorials. You may download the necessary software by clicking on the "Get It Now" button below.

 

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 specimen images, in addition to the initial randomly chosen one. The histogram of the brightness values in the image is shown in the right-hand Histogram window. Clicking on the Grayscale Orientation button shows the processed result for the image and histogram, illustrating the introduction of brightness differences that can be thresholded to select the various regions. Clicking on the Color Orientation button substitutes colors for the grayscale values in the processed image.

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: Wednesday, Mar 26, 2014 at 02:23 PM
Access Count Since July 20, 2006: 3474
For more information on microscope manufacturers,
use the buttons below to navigate to their websites: