Practical SfM Balancing: How Acquisition Parameters Affect Computation Time & Reconstruction Quality
Channel: Recording Archaeology
Date: 2019-10-23

Under perfect conditions, the best possible Structure from Motion (SfM) 3D model would be achieved by acquiring the largest number of photos using a camera of highest resolution. However, in reality the resolution is limited by the camera used and the time available onsite constrains the total number of images taken. Furthermore these constraints are directly linked to the computational time and quality of the SfM reconstruction. To determine the dependency between image resolution, number of images, computational time and accuracy of the resulting 3d model, we performed a series of a experiments, which can be categorized in two types: The first set under controlled conditions concerning constant lighting, precise movements between camera and object and accurately measured shapes of the latter to produce quantitatively reliable results. The second set of experiments features application-related objects, such as parts of historic monuments and archaeological small finds. We examine the relation of camera resolution and number of images taken with the reconstruction time and quality of the model quantitatively. For quality analysis, we use precise models- obtained by a Breuckmann structured light scanner for small objects and a laser scanner for larger objects. Processing time is measured for a set of commercial and free SfM software.

(Christian Seitz, Benjamin Reh, Silvan Lindner)