The combination of shearing interferometer, Fourier-transform profilometry, phase unwrapping by lockup table method has resulted in a new and more powerful method of measuring surface profile. The technique permits the three-dimensional shape measurement of objects that have discontinuous height steps. Experimental results have demonstrated the validity of the principle. The combination of shearing interferometer, Fourier-transform profilometry, phase unwrapping by lockup table method has resulted in a new and more powerful method of measuring surface profile. The technique permits the three-dimensional shape measurement of objects that have discontinuous height steps. have demonstrated the validity of the principle.