060074 UE Image-based modelling for archaeology (2024W)

Why this course?
Archaeology has always been in search of cost-effective approaches that acquire accurate three-dimensional (3D) geometry. Ideally, these workflows should also be straightforward to implement. Until 1.5 decades ago, acquiring detailed and accurate 3D geometry using images (a process called Image-Based Modelling or IBM) was a task that only photogrammetric experts could fulfil. However, this situation has dramatically changed due to the many new insights obtained in the field of computer vision. As a result, powerful image orientation techniques such as Structure from Motion (SfM) and dense image matching techniques like Multi-View Stereo (MVS) emerged and gradually complemented proven photogrammetric concepts. The combination of these new concepts with the increasing computational power that became available to average users has resulted in a new mapping and 3D modelling paradigm that currently affects various research fields.

This success story can largely be attributed to the ease of use of current IBM applications, the seemingly limited knowledge necessary to create a geometrical 3D model and the wide variety of frame imagery that can be used: old and new, colour and greyscale, airborne and terrestrial, large- and small-scale. Although many users consider IBM as an ideal means to yield visually pleasing, photo-realistic 3D models in a fast and straightforward way, many academic fields (such as archaeology) often rely on it to deliver (highly) accurate digital representations of real-world objects and scenes. However, this easiness of use makes many archaeologists unaware of the various pitfalls and technical difficulties that can still arise when using IBM. In addition, many 3D models are only merely created to ‘have a 3D model’, rather than to solve specific archaeological research questions.

Aim of this course
This course wants to remedy both issues by offering a very thorough introduction to the complete IBM pipeline: from image acquisition to the archaeological use of the generated 3D models, whether it is to research small artefacts, monitor excavations or survey complete landscapes with high-end orthophotographs. The course will start with a brief theoretical and practical coverage of the photographic principles that are essential for obtaining proper photographs for a 3D construction pipeline. However, students are expected to be already familiar with basic photographic concepts like exposure parameters (aperture, ISO and shutter speed), focal length, white balance and depth of field (see the compulsory literature). Using a variety of case studies, the theory and practice of IBM will be taught in Agisoft Metashape Professional. The image sets and exercises will gradually increase in complexity so that students can become familiar with the software while learning how to solve real-world IBM problems. If time permits, the usage and dissemination of these 3D models will be discussed: ‘How can they be shared?’; ‘How can new (geometrical) information be derived from them?’.

Methods used in this course
This course will consist of some theoretical lectures (supported by two pieces of literature), but most time will be devoted to the practice of photography and the IBM exercises. Students will learn how to critically undertake any archaeological IBM task and assess what information can be obtained from 3D surface models.

Expectations
Students are expected to bring a decent camera along (i.e., a camera that enables to manually dial in exposure settings; certainly no smartphone) and ideally have their own laptop. Moreover, students are expected to be familiar with standard Windows software and master English sufficiently well (hearing, speaking, and writing).