Several lectures following the Midterm Break will be devoted to the components that make up Digital Image Analysis (DIA). However, since you will begin using IDRISI and start exploring digital image analysis in your next lab, I thought it best that you be given a brief overview of DIA before delving into IDRISI.

The following processes are considered part of digital image analysis:

• Pre-processing (in particular, geometric registration or georegistration)
• Image enhancement
• Classification
  • Unsupervised
  • Supervised
• Change detection
• Data merging and GIS integration

In order to prepare you for the subsequent labs, which involve classifying satellite images, the lecture order (following the midterm break) will be different from the 'natural' order of digital image analysis presented above. That is, the image classification techniques--unsupervised and supervised classification--will be presented before the lecture on pre-processing.

Some interesting links:

• NASA has developed an interactive site that allows you to explore NDVI and other image processing techniques.
• The home page of Definiens, a company the develops advanced image processing software.
• The European Space Agency's newsletter on monitoring disasters.
• A site that provides a link to some free image processing software as well as a set of simple instructions (and data) on image classification.

A very useful web site--Eduspace-- that encourages teachers to use Earth observation data in their curriculum by providing ready-made projects. It is rich in didactical material, especially in local and global remote sensing satellite data. This website is produced by the European Space Agency (ESA), and includes a free downloadable image processing program called LEOWorks.

Text: Chapter 5: Visualization and radiometric processing; Chapter 8: Digital image classification