  We consider the ordinary and noncommutative Dirac-Born-Infeld theories within
the open string sigma-model. First, we propose a renormalization scheme, hybrid
point splitting regularization, that leads directly to the Seiberg-Witten
description including their two-form. We also show how such a form appears
within the standard renormalization scheme just by some freedom in changing
variables. Second, we propose a Wilson factor which has the noncommutative
gauge invariance on the classical level and then compute the sigma-model
partition function within one of the known renormalization scheme that
preserves the noncommutative gauge invariance. As a result, we find the
noncommutative Yang-Mills action.
