Inspection of surface integrity in additive manufacturing (AM) parts essentially needs a detailed understanding of their actual surface topography. Today's optical surface topography and roughness measurement sensors only provide information of the discrete points measured from the manufactured surface and not a detailed reconstruction of the surface topography. This paper presents a finite difference approach for reconstruction of the surface topography using sample measured data points. The developed methodology can be used in the surface quality inspection of the additive manufactured parts, their surface texture modeling, surface integrity analysis, and in planning for the required postprocessing or down-stream surface finish processes suitable for them. The methodology is fully implemented, and variety of experiments is conducted. The results show that the developed methodology is successful to reconstructed surface topography of the AM parts.