NIE July 2011 Lower Secondary Workshop E Stanley and M. Waterman

Adapted from Counting Sheep: Image Analysis (Neuhauser (2009) and Getting Started with Image Analysis (Stanley & Whitaker, 2010)

Exploring Data in Images with ImageJ

ImageJ is a National Institutes of Health resource for processing and analyzing images.

The software can be downloaded from the ImageJ web site: More documentation can be found at: and tutorials are found at:

Learning Objectives

You will be able to

  • open images in ImageJ
  • perform simple image analysis (measuring)
  • record and use image data to support conclusion

Knowledge and Skills

  • using imaging software for image analysis
  • mathematical concepts: setting the scale
  • measurement of area and length for objects
  • making screen captures (optional)

Introduction

In an increasingly visual society, learners are expected to retrieve and use information to make evidence-based conclusions. The use of images and the data they provide are necessary for many kinds of research. Both images and tools for image analysis are accessible online.

ImageJ is public domain software that can be downloaded on a variety of platforms, including Windows and Mac. The software can convert many image formats including GIF, JPEG, and TIFF to to 8-bit, 16-bit, or 32-bit images, which can then be analyzed by ImageJ.

Open ImageJ

Double click ImageJ(microscope icon) and then use File to Open the image SgHarbor.jpg located on the workshop webpage on the schedule for Thursday afternoon.

The image below is a screen capture from GoogleMaps in satellite view.

Measuring Objects

Setting the scale is necessary to make accurate measurements.

Click on the Straight Line Tool (5 squares in from the left) in the toolbar at the top of the screen.

Now measure the scale bar in the bottom left of the image. Draw a straight line equal to the 200 m length. Then, choose Analyze from the menu bar and click on Measure.Now select Set Scaleand enter the Known Distanceas 200 and then the Unit of Length as meters. Click on Global and OK to record further measurements.

Use the Straight Line Tool to determine the length of the largest ship. You will need to select Analyze and then Measure for the record to appear in the results table. Record length of the Singapore ship:

______meters

Now repeat the process for the image HongKongHarbor.jpgon the workshop website at on the Thursday afternoon schedule.

Record the length of the largest Hong Kong ship:

______meters

Part 2. Choose Images to Analyze

In small groups, please select an image or two your students might explore to answer a question of their own. It is important that you find images with a scale bar or with an object of known size.

You may wish to make a screen capture. This is simple to do.

For Windows computers, press Alt and Print Screen at the same time. A copy of the image will be stored on your clipboard. You can paste it into PowerPoint by pressing Ctrl and V at the same time. Then select it using a right click to see the menu below. Click on Save as Picture to use with ImageJ.

On Maccomputers, press Shift, Command, and #at the same time. A numbered picture file will be saved to your desktop.

We will share our ImageJ activities.

Photo Credit:

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