Using the strategy pattern to simplify ITK

ITK is becoming increasingly complex as it continues to grow and evolve. The SimpleITK initiative aims to address this concern by providing an easy-access layer around ITK for non-C++ expert developers. This article proposes an alternate (perhaps complementary) approach utilizing the strategy pattern. The software design pattern known as "strategy" allows an algorithm to be selected from a family of algorithms on-the-fly at runtime. Because ITK consists of many such algorithm families, this particular design pattern is quite interesting. This article describes a number of algorithm families which have been identified; so far thirteen families have been implemented, encapsulating nearly 130 filters/objects. Complete source code and examples are provided to demonstrate the concept.