In this letter, we study the problem of designing an efficient power and bit allocation scheme in the context of a hierarchical image transmission system based on an embedded multi-carrier modulation (EMCM) scheme over digital subscriber line. Authors describe a novel algorithm that performs power minimization under bit rate constraint and QoS requirement. It is based on the Hughes-Hartogs algorithm, and successively allocates the bits of the high, then low priority data streams. Simulations that assess the performance of the proposed algorithm are also provided and discussed; they demonstrate the interest of the proposed scheme.