ImageAlgorithm backward incompatible change

The following commit

has introduced a backward incompatible change (see for example RTK’s issues). Is this intentional? I have the feeling that defining a default template would have avoided this… but I’m guessing I’m missing something. Thanks in advance!
@matt.mccormick @grothausmann.roman

No, the backwards incompatible change was not intentional – thanks for the report @simon.rit.

Please review this patch, which adds a compatibility function: