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Weekly Research Seminars

This page contains a list with next and coming talks on our weekly seminars in Computer Vision (CV) and Natural Language Processing (NLP).

If you want to be included in the Computer Vision (CV) mailing list, please contact: <alba.garcia(at)> or <e.yagis(at)>

For past seminars see here.

27 January 2021 – CV – Zoom Meeting

Title: Beyond Validation: Characterising Modes of Segmentation Failure by Tasos Papastylianou

Abstract: Validation typically answers the question “to what extent does a segmentation algorithm work?”. However, this fails to address the equally interesting questions of why, when, or how an algorithm succeeds or fails. In many clinical applications, these are non-trivial questions, since some failures may be more clinically relevant than others. We demonstrate how modes of segmentation failure can be investigated in an anatomically meaningful manner with the use of appropriate fuzzy maps / masks, which can be straightforwardly constructed to express meaningful anatomical relationships between a probabilistic segmentation object and its ground truth. This allows us to ask questions like “how much of the segmentation’s failure occurs near anatomical landmark X”, or “at an approximate distance Y from X”, “in the general direction of Z”, “twice as bad near X as near Z”, “how much of the failed parts are due to the presence of a particular anatomical substructure or anatomical artifact”, etc, thereby providing an extra layer of explainability to the validation process.

Bio:  Dr Tasos Papastylianou is a Senior Research Officer at the Brain-Computer Interfaces and Neural Engineering (BCI-NE) lab at the University of Essex, working on a US-UK Bilateral Academic Research Initiative (BARI) project led by Prof. Riccardo Poli, looking at human-AI collaborative decision-making. Prior to this, he worked as a Machine Learning and Biomedical Signal Processing researcher for the Nevermind Project (, involving intelligent tools and systems enabling depression self management in patients with secondary depression, led locally by Dr Luca Citi. He was awarded his DPhil in 2017, in the area of Biomedical Engineering and Healthcare Innovation, and specifically Medical Image Analysis at the University of Oxford. In the past he also worked as a qualified physician in the NHS and as a concert pianist. He is particularly interested in tackling problems involving applications of AI / ML in clinical practice.