Building facade detection using geometric planar constraints

Abstract

This paper describes the approach for detecting the building facade using geometric constrain. A planar building facade is only considered. Most of the building facade has the form of a rectangle, which is produced by two or more vertical and horizontal lines, which are orthogonal to each other on the building. The parallel lines in the 3D space are projected onto lines in the image plane that are grouped along the direction of vanishing points. Line segments are extracted from an image for estimating vanishing points. In order to cluster the line segments corresponding to respective a hypothesized vanishing point, J-linkage algorithm is used for simultaneous estimation of multiple models. After clustering the line segments, vanishing point is estimated by minimizing error between vanishing point and line segments of an image. Building facade is detected by using the relationship between vertical and horizontal vanishing points. Building has a cubic structure with two perpendicular planes, which meet at a line. The intersection points between two horizontal vanishing points are located on the intersection line of two facades. Finally, building facades are extracted by the geometric relationships between vertical vanishing point corresponding to respective horizontal vanishing point.