When specular surface is imaged on a group of CCD cells, the image usually suffers from saturation and blooming
problem. This problem is a serious obstacle to applying optical profiling methods based on structured light to specular
objects. In this paper, a phase-based profiling system combined with a spatial light modulator in the imaging part is
proposed to measure three dimensional shape of partially specular surfaces. The spatial light modulator prevents the
image sensor from being saturated. In this way, projected fringes are well imaged and their phase information is correctly
extracted. The system configuration and transmittance control scheme are explained in sequence. This idea is verified by
experimental results, in which phase information is successfully extracted from the areas which are not normally
measurable due to saturation.