1. A system for measuring displacement of an object surface comprising: a displacement sensor that projects a line on the object surface and receives light from the projected line at an imager in a manner defines a plurality of displacement values in a height direction; and a vision system processor that processes rows of imager pixels to determine a position of the projected line in columns of the imager pixels exclusively in each of a plurality of regions of interest, each of the regions of interest respectively defining a plurality of rows of imager pixels that correspond with expected locations of the projected line on the object surface, wherein of the position of the projected line in each of the columns corresponds to a physical displacement value on the object surface.