A method for characterizing a three-dimensional surface profile of a semiconductor workpiece is provided. In this method, the three-dimensional surface profile is imaged from a normal angle to measure widths of various surfaces in a first image. The three-dimensional surface is also imaged from a first oblique angle to re-measure the widths of the various surfaces in a second image. Based on differences in widths of corresponding surfaces for first and second images, a feature height and sidewall angle are determined for the three-dimensional profile.