You can calculate new Arithmetic Features for your image objects easily within eCognition. A very good example would be calculating the NDVI for your image objects. To do so, you can do the following:

1. Go to the Feature View window
2. Open the Object features
3. Open Customized
4. Double click on the Create new Arithmetic Feature
5. Within this window you can create your own Feature by entering a formula into the Calculation window via the calculator and feature interface. Note that you cannot type the name of features, you must select them from the menu. You also can give your new feature a meaningful name.
6. Once complete, click OK and the feature is added to the Feature View window.

The example below shows you how a new feature called “ndvi” can be created. Be creative and calculate new features and enjoy!

Alternatively, you can calculate an NDVI layer simply by using the index layer calculation algorithm. All you have to do is define the input layers! This algorithm supports the calculation of multiple standard indices.