Programme

Geert J. Verhoeven - University of Vienna, Austria

Parasitic pixels – How cameras (and their settings) can jeopardise image-based 3D modelling

Amongst many application-driven techniques developed by multiple disciplines, one possible approach for surface digitisation is via photographs (or more general images), commonly referred to as Image-Based (3D) (surface) Modelling or simply IBM. IBM encompasses different techniques, but most rely on object or scene photographs taken from different locations to extract digital surface data. IBM has been the focus of both photogrammetry and computer vision fields. However, hybrid photogrammetric computer vision-based approaches, like Structure from Motion (SfM), Simultaneous Localisation and Mapping (SLAM) and Multi-View Stereo (MVS), have become common place in 3D documentation over the last 15 years. This rapid technology uptake also led to an ever-increasing continuous stream of new literature, filled almost exclusively with software comparisons or developments towards faster and more automated approaches. However, one thing stands out in this story: the surprisingly little attention devoted to the input of all these algorithms: the photographs. Are digital cameras so ubiquitous, and have algorithms become so robust that academics stopped paying attention (if they ever really did?) to how a camera’s operating principles tailor the pixels they generate?

This talk will go back to the basics of all IBM approaches – pixels – and detail how camera architectures and settings affect their positional and spectral values. Various case studies will illustrate how the resulting sub-optimal or parasitic pixels can negatively affect the IBM output and which measures can mitigate such issues. Ultimately, the talk hopes to incentivise more awareness for, and academic research on, the basics of IBM: photography.

Jonathan Westin - University of Gothenburg, Sweden

Digitizing sensitive heritage monuments in Antarctica

In 2020, the remains of the Nordenskjöld expedition to Antarctica (1901-1903) were documented using a broad set of both traditional and digital techniques. Threatened by the impacts of climate change, the goal was to secure as much data as possible about the monuments, and make available a dataset that could support decision making for future conservation efforts and research. 

This talk details the 3D documentation effort and challenges in Antarctica and discusses how experts in different disciplines can use digital data to visit and diagnose sensitive or inaccessible environments.