Worksheet Classification-c03-ws02

Subjects:

Mathematics, Geography, Earth Science

Objectives:

In this exercise you learn how to use ILWIS for calculating a histogram on image data.

Prerequisite:

• The frequency distribution
• The relative frequency distribution
• Measures of value
• Introduction to the Image Processing Software ILWIS

Materials:

• Image Processing Software ILWIS (download from http://52north.org/)
• Landsat TM Image file of the Skagen Area, Denmark
  
  

Time needed:

1 or 2 school lessons, depending on your previous knowledge in working with ILWIS

Procedure:

1. Open ILWIS
   
   
2. Display the skagen image by double clicking on its icon in the maplist window.
   
   
3. Another window will open, listing the four channels in the image. Above this list is a symbol like a television. Click on this, then click on OK in the next displayed window and the image will display.
   
   
4. You can try various combinations of the bands, and you can try various forms of enhancement.
   
   
5. Below the image icon will appear three histogram icons. Double clicking on these displays the histograms and the cumulative histograms.