Day 3: Selection Techniques and Annotations

One of the key goals of digital image processing is to identify the features or characteristics in an image that you're interested in and to select only those pixels to analyze. ImageJ provides an extensive array of tools and techniques for enhancing images to differentiate and then to select those features for analysis. These regions of interest (ROIs) are often used to measure changes over time. ImageJ includes utilities to help save, manage, recall, and operate on these selections—a valuable time-saver in the research process.

The selection process is also fundamental to labeling or annotating images for publication and sharing. Both destructive and non-destructive annotation methods are available in ImageJ via a transparent annotation overlay that can be turned on and off as needed. Today's material will provide time-saving techniques for conducting scientific research projects using ImageJ.

Day 3 Goals

• Apply appropriate selection techniques to define a Region of Interest (ROI).
• Become skilled at using selection tools and tool options.
• Use selection techniques to annotate images both destructively and nondestructively.

Day 3 Tasks

1. Annotate a digital image using a variety of selection techniques.
2. Use the Region of Interest (ROI) Manager to save, manage, and recall selected study areas.
3. Select and measure areas of interest in your study image.

Sources

¹Adapted from Earth Exploration Toolbook chapter instructions under Creative Commons license Attribution-NonCommercial-ShareAlike 1.0.
²Adapted from Eyes in the Sky II online course materials, Copyright 2010, TERC. All rights reserved.
³New material developed for Earth Analysis Techniques, Copyright 2011, TERC. All rights reserved
⁴From Remote Sensing Math: A Brief Mathematical Guide by Dr. Sten Odenwald, NASA 2011.