Phase Analysis of Three-Dimensional Zernike Moment for Building Classification and Orientation in Digital Surface Model

In this letter, we proposed a phase analysis of the 3-D Zernike moment (3D-ZM), to estimate the orientation difference between buildings in a digital surface model (DSM). A 3-D analysis using the DSM is an important way for building reconstruction and many further remote sensing applications. By using the 3D-ZM, we could decompose the 3-D structure of an object in a complex domain. Benefiting from rotation invariance of the amplitude component, the 3D-ZM has excellent performance for object classification. However, the phase component of 3D-ZM is ignored in early research, by which orientation of different objects could be analyzed, and similar buildings (within one class) could be distinguished meticulously, whereas other traditional geometric features may fail to do so. Therefore, we studied the phase analysis of 3D-ZM and introduced a flow frame of orientation-difference estimation. Experimental results illustrated that our method could robustly find the orientation difference between similar buildings, and improvement on accuracy was achieved for building classification and orientation.