There are three principal approaches to correcting shading in images. The first, and the best for those cases in which is it practical, is to capture two images, one of the specimen and another with the specimen removed or replaced by a uniform target so that the pattern of nonuniformity can be recorded directly. This “background” image can then be either subtracted from or divided into the image of the specimen to produce a leveled result. This method can be very successful with photographs on a copy stand, or for some types of specimens in a transmission light microscope. This interactive tutorial illustrates background correction performed by subtracting an image of nonuniform illumination.

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 radio buttons show the Original image, the measured Background image, and the resulting image after Subtraction of the background from the original.

---

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 04:17 PM

Access Count Since July 20, 2006: 6208

For more information on microscope manufacturers,
use the buttons below to navigate to their websites: