I. Introduction
As an essential element in “smart city” construction, the position information of the bottom outline of buildings has become essential data for navigation and positioning. The vectorized position information of building footprints can clearly express the geometric form of a building, which can be crucial to urban geographic information and renewal. Higher requirements have been provided for the precision of building vector coordinates in the current urban development. Building extraction methods are based on dense point cloud data and remote sensing images. Compared with dense point cloud data, remote sensing technology can obtain full-coverage, large-scale, high real-time surface observation data, efficiently collecting large-scale building information. Accurate and automatic extraction of vectorized buildings from high-resolution remote sensing images is crucial to urban planning, map data updating, and emergency response.