Comparative analysis of homologous buildings using range imaging

This paper reports on a novel application of computer vision and image processing technologies to an interdisciplinary project in architectural history that seeks to help identify and visualize differences between homologous buildings constructed to a common template design. By identifying the mutations in homologous buildings, we assist humanists in giving voice to the contributions of the myriad additional “authors” for these buildings beyond their primary designers. We develop a framework for comparing 3D point cloud representations of homologous buildings captured using lidar: focusing on identifying similarities and differences, both among 3D scans of different buildings and between the 3D scans and the design specifications of architectural drawings. The framework addresses global and local alignment for highlighting gross differences as well as differences in individual structural elements and provides methods for readily highlighting the differences via suitable visualizations. The framework is demonstrated on pairs of homologous buildings selected from the Canadian and Ottoman rail networks. Results demonstrate the utility of the framework confirming differences already apparent to the humanist researchers and also revealing new differences that were not previously observed.