Hello Per, > > But what is 'this' argument, how do I 'grab it' from imagej/fiji plugin? > That is not a question about Kawa. It is a question about the imagej/fiji plugin. > How would you get the 'this' argument in a Java program? > ... I actually figured it out before to read your 2nd email, but of course thanks a lot for your answers, and, yes, a java related quizz, plus how to implemented it in kawa... It would have been a lot more productive though, if you allow me, to answer (your first answer) something like [*] ... these methods always expect, as their first _implicit_ argument, an instance of the class that 'holds' the methods [*]. so in this case: (define-alias ltw-new sc.fiji.localThickness.LocalThicknessWrapper:new) (process-image (ltw-ew) iplus) Cheers, David [*] 'this' really didn't mean anything to me