Facade parsing aims to decompose a building facade image into semantic regions of the facade objects. Considering each architectural element on a facade as a parameterized rectangle, we formulate the facade parsing task as object detection, allowing overlapping and nesting, which will support structural 3D modeling and editing for further applications. In contrast to general object detection, the spatial arrangement regularity and appearance similarity between the facade elements of the same category provide valuable context for accurate element localization. In this paper, we propose to exploit the spatial arrangement regularity and appearance similarity of facade elements in a detection framework. Our element-arrangement context network (EACNet) consists of two unidirectional attention branches, one to capture the column-context and the other to capture row-context to aggregate element-specific features from multiple instances on the facade. We conduct extensive experiments on four public datasets (ECP, CMP, Graz50, and eTRIMS). The proposed EACNet achieves the highest mIoU (82.1% on ECP, 77.35% on Graz50, and 82.3% on eTRIMS) compared with the state-of-the-art methods. Both the quantitative and qualitative evaluation results demonstrate the effectiveness of our dual unidirectional attention branches to parse facade elements.

Reconstruction of man-made scenes from multi-view images is an important problem in computer vision and computer graphics. Observing that man-made scenes are usually composed of planar surfaces, we encode plane shape prior in reconstructing man-made scenes. Recent approaches for single-view reconstruction employ multi-branch neural networks to simultaneouslysegment planes and recover 3D plane parameters. However, the scale of available annotated data heavily limits the generalizability and accuracy of these supervised methods. In this paper, we propose multi-view regularization to enhance the capability of piecewise planar reconstruction during the training phase, without demanding extra annotated data. Our multi-view regularization enables the consistency among multiple views by making the feature embedding more robust against view change and lighting variations. Thus, the neural network trained by multi-view regularization performs better on a wide range of views and lightings in the test phase. Based on more consistent prediction results, we merge the recovered models from multiple views to reconstruct scenes. Our approach achieves state-of-the-art reconstruction performance compared to previous approaches on the public ScanNet dataset.