Example 3 - Performing a supervised classification

This example shows how to perform a supervised classifiation using InterIMAGE.


Example 3 - Database

This zip file contains:

  • tijuca.tif

Step by step

  • Start InterIMAGE. Click on FileNew Project and fill the fields according to the following:

New Project

  • Check the Default Image checkbox and click the Add button. Click OK.
  • Create a semantic net like this one:

(Class names shouldn't contain blank spaces or special characters) Semantic net

  • Select the Image tab and click the Add button. Set its Keyname to composed and click the Composition button.

Image layer

  • In the dialog that appears set the color composition according to the image below:

Color Composition dialog

  • Close the dialog. Click Save. Another image layer is added and you should see something like this:

Image layer added

  • Save the project. Select the Scene node and click the Samples Editor button.

Open Samples Editor

  • Maximize the window that appears. Select the TA_Baatz_Segmenter operator. Set its parameters according to the following:

Selecting the operatorSetting the operator parameters

  • Click the Segment button. Once the segmentation is finished, make sure the Buildings class is selected and click the Collect Samples button.

Collect samples

  • Now, click on some objects that belong to the Buildings class (To deselect an object just click it again).

Collecting samples

  • When you are done, repeat the process to the other two classes. Setting the Background Image to the other composition created previously can be helpful here.
  • After, click the Collect Samples again, deselecting it.
  • Click the Export button. In the window that appears click the Class button. Select All and click OK.

Export ShapefileInsert Class

  • Click the Expression button. Set the fields according to the image below:

Insert Expression

  • After, create another three expressions. Your decision rule should look like this:

Decision Rule

  • Click OK. Set the file name to samples.shp and Click Save.
  • Save the project. Once the project is saved click on FileEdit Project. Fill the fields according to the following:

Edit Project dialog

  • Click the Add button and then click OK.
  • Associate the TA_C45_Classifier top-down operator to the Buildings node. Set the operator parameters according to the image below. Make sure the TopDown Multi-class checkbox is checked.

Selecting the operatorSetting its parameters

  • Save the project and execute the interpretation.
  • You can improve your classification collecting more samples for the classes that presented more confusion and repeating the process.