The class.getResourceAsStream() Java method allows to load files through the class loader relative to the calling class. This is very convenient because one can package for example template images together with the Java test code into one class path or even JAR file.
This way of loading files works well when Java test scripts are executed independently using their own main() method. It however fails when Java source code (.java) is executed by T-Plan Robot either through CLI or from the GUI. The files do not seem to be loaded from the same directory as the Java source code file.