A surface measurement module for 3-D image acquisition of a subject-under-inspection. The module having: (a) a casing to house a pattern shifting device having a fixed-pattern optic through which light from a light source is passed, an output of the pattern shifting device being directed at a polarizing beam splitter and the polarized output of the splitter directed through a lens assembly comprising at least one lens element; (b) a reflector to direct the polarized output exiting the lens assembly, to illuminate a surface of the subject-under-inspection; (c) a scattered light illumination off the surface is directed back through the lens assembly for capture by an image sensor; and (d) the casing also housing the polarizing beam splitter, the lens assembly, and the image sensor. The output of the fixed-pattern optic comprises a multi-frequency pattern. The pattern shifting device may be a linear or rotating type.