Centrum Wiskunde & Informatica (CWI) has a vacancy in the Computational Imaging research group for a talented PhD student (m/f/x).
on the subject of “Computational Aspects of Novel Image Representation Techniques for Computed Tomography”
Job description
X-ray Computed Tomography (CT) is the most versatile 3D imaging technique to reveal the interior of static objects with high spatial resolution. It is indispensable in an increasing range of applications in science, health care and industry. However, despite considerable research, state-of-the-art image reconstruction methods fail to resolve dynamic processes with both high spatial and temporal resolution (4D CT). This PhD position is part of a joint research project between CWI and Ghent University (UGhent) that will develop new image reconstruction techniques that allow to realize the full potential of CT to reveal, analyze, control or optimize dynamical processes.
To overcome the bottlenecks of traditional 4D CT image reconstruction techniques, we will investigate new techniques to represent the dynamic objects: Instead of representing them as 4D arrays of numerical values, we will use new, differentiable representations relying on techniques such as neural networks (Implicit Neural Representations), Gaussian primitives (Gaussian Splatting) or adaptive sparse voxels rasterization. The PhD position will develop fast and memory efficient ways to utilize these representations for CT image reconstruction. In particular, we will integrate the representations with the GPU computing primitives that model CT data acquisition (https://astra-toolbox.com/), develop PyTorch building blocs that are memory-efficient enough for 4D image represenation, and research new methods for computing the differentiable representations directly from CT data, such as coarse-to-fine multigrid optimization schemes. We will publish an open software implementation of the developed methods and showcase their potential on important, high-resolution, real-world applications of dynamic CT imaging.
The project relies on the unique combination of CWI’s Computational Imaging group’s expertise in translating sophisticated image reconstruction techniques to real-world applications, a network of collaborations and our group’s software developments, experimental facilities and computational resources. The PhD candidate will be supervised by Felix Lucka, Tristan van Leeuwen and Alexander Skorikov and will be part of a large, dynamic research group together with other PhD candidates, postdoctoral and senior researchers that work on a variety of topics in computational imaging. Regular seminars and meetings facilitate a stimulating and supportive environment with many opportunities for both scientific exchange and personal development.
Furthermore, the project is a collaboration between CWI’s Computational Imaging group, the Image Processing and Interpretation (IPI, http://ipi.ugent.be ) research group at UGhent and the Radiation Physics research group at the Center for X-ray Tomography at UGhent (UGCT, http://www.ugct.ugent.be ). In addition to regular meetings with the PhD student and postdoc employed at UGhent, the PhD candidate will also have the opportunity to spend extended research visits at UGhent and visit other international research groups for exchange and collaboration. The PhD student and will learn how to present and disseminate the results of their work at the most important international conferences for the topical area, such as NeurIPS, SIAM Imaging Science, or ICIAM.
Requirements
- Candidates are required to have a strong background in Computational Mathematics and a Master’s degree in Mathematics, Computer Science, Physics, Electrical Engineering or a related discipline.
- Good programming skills and the ability to work both independent and in a research team are essential.
- Preferable qualifications for candidates include proven research talent, an excellent command of English and good academic writing and presentation skills.
Terms and conditions
The terms of employment are in accordance with the Dutch Collective Labour Agreement for Research Centres ("CAO-onderzoeksinstellingen"). The initial labour agreement will be for a period of 18 months. After a positive evaluation, the agreement will be extended by 30 months. The gross monthly salary, for a PhD student on a full time basis, is € 3,115 during the first year and increases to € 3,989 over the four year period. Employees are also entitled to a holiday allowance of 8% of the gross annual salary and a year-end bonus of 8.33%. CWI offers attractive working conditions, including flexible scheduling and help with housing for expat employees.
Please visit the CWI website for more information about our terms of employment’, or go to the working pages of the NWO website
Information and application
The PhD position can start between 1 June 2026 and 15 September 2026. Applications can be sent until 19 April 2026 to apply@cwi.nl . All applications should include a detailed resume (CV), motivation letter, list of your MSc courses and grades and a copy of your Master’s thesis.
Candidates may apply prior to obtaining their master's degree, but cannot begin before having received it (within the probationary period of the first 2 months).
For more information about the vacancy, please contact Felix Lucka, Felix.Lucka@cwi.nl.
For more information about CWI, please visit www.cwi.nl or watch our video about working at CWI.
CWI encourages a diverse workforce: we endeavor to develop talent and creativity by bringing people from different backgrounds and cultures together. We recruit and select based on capabilities and talent. We strongly encourage everyone with the appropriate qualifications to apply for the vacancy, regardless of age, gender, origin, sexual orientation or physical abilities.
Diversity code
CWI strives to be a diverse and inclusive research institute. To achieve balanced representation in positions, we have been investing in a diverse and inclusive organization already since 2010, among others by prioritizing applications from women researchers. This approach has recently led to hiring a majority of women in Tenure Track positions.
CWI encourages a diverse workforce: we endeavour to develop talent and creativity by bringing people from different backgrounds and cultures together. We strongly encourage candidates with the appropriate qualifications to apply for the vacancy, regardless of age, origin, sexual orientation or physical abilities.
About CWI
Centrum Wiskunde & Informatica (CWI) is the Dutch national research institute for mathematics and computer science and is part of the Institutes Organisation of the Dutch Research Council (NWO). The mission of CWI is to conduct pioneering research in mathematics and computer science, generating new knowledge in these fields and conveying it to trade, industry, and society at large.
CWI is an internationally oriented institute, with 160 scientists from approximately 27 countries, an informal atmosphere and short lines of communication. We have an activity committee that organizes after-work activities and among others a women’s network.
CWI is located at Science Park Amsterdam, which is a major location of research in the physical sciences in The Netherlands, housing the sciences of the University of Amsterdam as well as several other national research institutes next to CWI.
About Research group
To find more information about the Computational Imaging group, please visit the group page.
https://www.cwi.nl/en/groups/computational-imaging/
