Image-based 3D capture of cultural heritage artifacts an experimental study about 3D data quality

The paper presents an analysis of the 3D data quality generated from small-medium objects by well-known automatic photogrammetry packages based on Structure from Motion (SfM) and Image Matching (IM). The work aims at comparing different shooting configurations and image redundancy, using as high-quality reference the 3D data acquired by triangulation-based laser scanners characterized by a low measurement uncertainty. Two set of tests are presented: i) a laboratory 3D measurement made with the two active and passive approaches, where the image-based 3D acquisition makes use of different camera orientations leading to different image redundancy; ii) a 3D digitization in the field with an industrial laser scanner and two sets of images taken with different overlap levels. The results in the field confirm the relationship between measurement uncertainty and image overlap that emerged in the Lab tests.