Deformed algebras from the inverse Schwinger method

We consider a problem which may be viewed as inverse to the Schwinger realization of Lie algebra, and suggest a procedure for deforming the algebra so obtained. We illustrate the method through a few simple examples extending Schwinger's su(1,1) construction. As results, various q-deformed algebras are (re-)produced as well as their undeformed counterparts. Some extensions of the method are briefly pointed out.