  We consider a problem which may be viewed as an inverse one to the Schwinger
realization of Lie algebra, and suggest a procedure of deforming the
so-obtained algebra. 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 pointed out briefly.
