He has broad multi-disciplinary research interests in applied mathematics, statistics, and computer science, with main focus and applications in

• 🔎 image/signal/data processing
• 🔎 computer vision
• 🔎 machine learning
• 🔎 optimisation

In particular, he is also interested in, but not limited to

• segmentation and classification
• pattern recognition
• image reconstruction
• image registration
• wavelets

and their applications in, but not limited to

• digital imaging
• medical imaging
• remote sensing
• radio interferometric imaging
• big-data analysis

Invited Conference Talks

• 30-min Talk, Recent Advances in Theories and Applications of Data Science, TSIMF, Sanya, China. 02–06 Dec. 2019

• 20-min Talk, 27th European Signal Processing Conference (EUSIPCO), A Coruna, Spain. 02–06 Sept. 2019

• 20-min Talk, Statistical Challenges in 21st Century Cosmology (COSMO21), Valencia, Spain. 22–25 May 2018

• 45-min Talk, One Day on Compressive Sensing – Advances in theory, algorithms, and applications, Bath, UK. 01 June 2017

• 30-min Talk, Turing/LMS Workshop – Inverse Problems and Data Science, Edinburgh, UK. 08–10 May 2017

• 30-min Talk, The Eighth International Conference – Inverse Problems: Modeling and Simulation, Fethiye, Turkey. 23–28 May 2016

• 50-min Talk, The Third International Workshop on Image Processing Techniques and Applications, incorporating Mathematical Imaging with Biomedical Applications, Liverpool, UK. 06–08 July 2015

• 5-min Talk, Challenges in Dynamic Imaging Data, Cambridge, UK. 09–11 June 2015

• 30-min Talk, SIAM Conference on Imaging Science (SIAM-IS14), Hong Kong. 12–14 May 2014

• 30-min Talk, SPOC 2013 (Int. Conf. Signal Processing, Optimization and Compressed Sensing), Harbin, China. 27–31 Dec. 2013

• 25-min Talk, 9th Intl. Conf. on Energy Minimization Methods in Computer Vision and Pattern Recognition (EMMCVPR, 2013), Lund, Sweden. 19–21 Aug. 2013

• 30-min Talk, 11th European Congress of Stereology and Image Analysis 2013, Kaiserslautern, Germany. 08–12 July 2013

• 30-min Talk, The 9th East Asia SIAM Conference (EASIAM 2013), Bandung, Indonesia. 18–20 June 2013

• 15-min Talk, Student Paper Competition, IEEE-EMBS Hong Kong Chapter, HKPC Building, Hong Kong. 20 Aug. 2011

Visiting Scholar or Seminar Talks

• 1-hour Talk, The School of Mathematics & Statistics, University of Glasgow, Glasgow, UK. 20 Nov. 2019

• 20-min Talk, Department of Physics and Mathematics, Nottingham Trent University, Nottingham, UK. 19 Nov. 2019

• 40-min Talk, School of Electronics and Computer Science, University of Southampton, Southampton, UK. 15 Nov. 2019

• 40-min Talk, Department of Mathematical Sciences, University of Essex, Colchester, UK. 13 Nov. 2019

• 1-hour Talk, DAMTP, Cambridge University, Cambridge, UK. 11 Nov. 2019

• 30-min Talk, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK. 01 July 2019

• 10-min Talk, (Astro Jamboree), Mullard Space Science Laboratory, University College London, Surry, UK. 13 Dec. 2018

• 1-hour Talk, DAMTP, Cambridge University, Cambridge, UK. 03 June 2016

• 1-hour Talk, Mullard Space Science Laboratory, University College London, Surry, UK. 13 May 2016

• 30-min Talk, Department of Computer Science, University of Dundee, Dundee, UK. 25 Feb. 2015

• 30-min Talk, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK. 27 Jan. 2015

• 1-hour Talk, Department of Mathematics, Hong Kong Baptist University, Hong Kong. 22 Dec. 2014

• 25-min Talk, Division of Medical Physics, University of Leeds, Leeds, UK. 03 Dec. 2014

• 30-min Talk, VoxTox Progress Meeting, Cambridge University, Cambridge, UK. 08 Oct. 2014

• 25-min Talk, Young Scientist Award Competition, Hong Kong Institution of Science, Hong Kong. 06 Nov. 2013

• 1-hour Talk, Department of Mathematics, National University of Singapore, Singapore. 25 June 2013

• 1-hour Talk, Institute of Biomathematics and Biometry of Helmholtz Zentrum Muenchen, Munich, Germany. 14 May 2012

• 1-hour Talk, Department of Mathematics, Technische Universit"at Kaiserslautern, Kaiserslautern, Germany. 08 May 2012

• Uncertainty quantification and computational imaging workshop, Edinburgh, UK. 23–24 Apr. 2018}

• Variational methods and effective algorithms for imaging and vision, Cambridge, UK. (29th Aug 2017–20th Dec 2017). 05–08 Nov. 2017

• Poster, Workshop on New Mathematical Methods in Computational Imaging, Edinburgh, UK. 29 June 2017

• Poster, 3rd UCL Workshop on the Theory of Big Data, London, UK. 26–28 June 2017

• Poster, International BASP Frontiers workshop, Villars-sur-Ollon, Switzerland. 29 Jan.–03 Feb. 2017

• SKA – Delivering the Science, Cambridge, UK. 12–13 Apr. 2016

• SuSTaIn EdgeCutter One Day Workshop on High-dimensional Statistics, Inverse Problems and Convex Analysis, Royal Statistics Society, London, UK. 22 Mar. 2016

• Data Science and Health Alan Turing Institute Summit, Cambridge, UK. 21 Sept. 2015

• Software Carpentry Workshop, London, UK. 18–19 June 2015

• Computational Radiotheray Symposium, Cambridge, UK. 17 June 2015

• Cambridge SIAM Chapter Launch Conference, Cambridge, UK. 27 Apr. 2015

• Plant Sciences Department Research Day, Cambridge, UK. 11 Dec. 2014

• NC3Rs Follow-up Meeting, Oxford, UK. 19–23 Nov. 2014

• NC3Rs/POEMS Network Maths Study Group: Apply Mathematics to 3Rs problems, Cambridge, UK. 09–12 Sept. 2014

• A symposium to celebrate David Hanke's contribution to teaching and research in the Department, Cambridge, UK. 02 Sept. 2014

• Chemical Safety Training, Cambridge, UK. 15 July 2014

• Poster, Advances in Mathematical Image Processing (AIP), Annweiler, Germany. 30 Sept.–02 Oct. 2013

• International Conference on Scientific Computing: In honor of Prof. Tony F. Chan at his 60th birthday for his contributions to Scientific Computing, Hong Kong. 4–7 Jan. 2012

• Opening Workshop of the Forth International Summer School on Numerical Linear Algebra, Guiyang, China. 14–30 July 2011

• The 3rd Workshop on Numerical Algebra and Scientific Computation, Hong Kong. 26–27 Mar. 2011

• H. Aysel, X. Cai, and A. Prugel-Bennett. Multilevel Explainable Artificial Intelligence: Visual and Linguistic Bonded Explanations. IEEE Transactions on Artificial Intelligence, DOI: https://doi.org/10.1109/TAI.2023.3308555, 2023.

• J. Hollister, X. Cai, T. Horton, B. Price, K. Zarzyczny, and P. Fenberg. Using Computer Vision to Identify Limpets from Their Shells: a Case Study Using Four Species from the Baja California Peninsula. Frontiers in Marine Science, DOI: https://doi.org/10.3389/fmars.2023.1167818, 2023.

• W. Dong, G. Yu, L. Qi, and X. Cai. Practical Sketching Algorithms for Low-Rank Tucker Approximation of Large Tensors. Journal of Scientific Computing, DOI: https://doi.org/10.1007/s10915-023-02172-y, 2023.

• K. Alomar, H. Aysel, and X. Cai. Data Augmentation in Classification and Segmentation: A Survey and New Strategies.
  Journal of Imaging, DOI: https://doi.org/10.3390/jimaging9020046, 2023.

• M. Du, P. Zhong, X. Cai, D. Bi, and A. Jing. Robust Bayesian Attention Belief Network for Radar Work Mode Recognition.
  Digital Signal Processing, DOI: https://doi.org/10.1016/j.dsp.2022.103874, 2023.

• M. Du, P. Zhong, X. Cai, D. Bi, and Z. Li. Balanced Neural Architecture Search and Optimization for Specific Emitter Identification. 2022 IEEE 12th International Conference on RFID Technology and Applications (RFID-TA), pp. 220–223, doi: 10.1109/RFID-TA54958.2022.9924146, 2022.

• X. Cai, J. McEwen, and M. Pereyra. High-dimensional Bayesian Model Selection by Proximal Nested Sampling. Statistics and Computing, 32(5):1–22, 2022.

• Z. Liang, W-T. Yeung, K. Mai, J. Ma, Z. Liu, Y. Chong, X. Cai, and B.-H. Kang. CURT1A and CURT1C Mediate Distinct Stages of Plastid Conversion in Arabidopsis Cotyledon. The Plant Cell, 34(10):3830–3843, 2022.

• M. Du, P. Zhong, X. Cai, and D. Bi. DNCNet: Deep Radar Signal Denoising and Recognition. IEEE Transactions on Aerospace and Electronic Systems, 58(4):3549–3562, 2022.

• M. Du, X. He, X. Cai, and D. Bi. Balanced Neural Architecture Search and Its Application in Specific Emitter Identification. IEEE Transactions on Signal Processing, 69:5051–5065, 2021.

• D. Mallios and X. Cai. Deep Rectum Segmentation for Image Guided Radiation Therapy with Synthetic Data. European Signal Processing Conference (EUSIPCO), pp. 975–979, 2021.

• M. Price, J. McEwen, X. Cai, T. Kitching, and C. G. R. Wallis. Sparse Bayesian Mass-mapping with Uncertainties: Hypothesis Testing of Structure. Monthly Notices of the Royal Astronomical Society (MNRAS), 506(3):3678–3690, 2021.

• X. Cai, R. Chan, and T. Zeng. An Overview of SaT Segmentation Methodology and Its Applications in Image Processing. Handbook of Mathematical Models and Algorithms in Computer Vision and Imaging: Mathematical Imaging and Vision, Springer International Publishing, pp. 1–27, 2021.

• M. Price, X. Cai, J. McEwen, M. Pereyra, and T. Kitching. Sparse Bayesian Mass-mapping with Uncertainties: Local Credible Intervals. Monthly Notices of the Royal Astronomical Society (MNRAS), 492(1):394–404, 2020.

• X. Cai, C. G. R. Wallis, J. Y. H. Chan, and J. D. McEwen. Wavelet-based Segmentation on the Sphere. Pattern Recognition, 100, https://doi.org/10.1016/j.patcog.2019.107081, 2020.

• J. Williams, C.-B. Schonlieb, T. Swinfield, J. Lee, X. Cai, L. Qie, and D. Coomes. 3D Segmentation of Trees Through a Flexible Multiclass Graph Cut Algorithm. IEEE Transactions on Geoscience and Remote Sensing, 58(2):754–776, 2020.

• X. Cai, R. Chan, C.-B. Schonlieb, G. Steidl, and T. Zeng. Linkage Between Piecewise Constant Mumford-Shah Model and Rudin-Osher-Fatemi Model and Its Virtue in Image Segmentation. SIAM Journal on Scientific Computing, 41(6):B1310–B1340, 2019.

• M. Price, J. McEwen, X. Cai, and T. Kitching. Sparse Bayesian Mass-mapping with Uncertainties: Peak Statistics and Feature Locations. Monthly Notices of the Royal Astronomical Society (MNRAS), 489(3):3236–3250, 2019.

• X. Cai, M. Pereyra, and J. McEwen. Quantifying Uncertainty in High Dimensional Inverse Problems by Convex Optimisation. European Signal Processing Conference (EUSIPCO), 2019.

• X. Cai, L. Pratley, and J. McEwen. Online Radio Interferometric Imaging: Assimilating and Discarding Visibilities on Arrival. Monthly Notices of the Royal Astronomical Society (MNRAS), 485(4):4559–4572, 2019.

• X. Cai, R. Chan, H. Yang, and T. Zeng. Smoothing and Thresholding - a Flexible Methodology for Image Segmentation. SIAM news, 2019.

• X. Cai, M. Pereyra, and J. McEwen. Uncertainty Quantification for Radio Interferometric Imaging: II. MAP Estimation. Monthly Notices of the Royal Astronomical Society (MNRAS), 480(3):4170–4182, 2018.

• X. Cai, M. Pereyra, and J. McEwen, Uncertainty Quantification for Radio Interferometric Imaging: I. Proximal MCMC Methods. Monthly Notices of the Royal Astronomical Society (MNRAS), 480(3):4154–4169, 2018.

• With N. Burnet, et al. Applying Physical Science Techniques and CERN Technology to an Unsolved Problem in Radiation Treatment for Cancer: the Multidisciplinary “VoxTox” Research Programme. CERN IdeaSquare Journal of Experimental Innovation, 1(1):3, DOI: http://dx.doi.org/10.23726/cij.2017.457, 2017.

• X. Cai, R. Chan, M. Nikolova, and T. Zeng. A Three-stage Approach for Segmenting Degraded Color Images: Smoothing, Lifting and Thresholding (SLaT). Journal of Scientific Computing, 72(3):1313–1332, 2017.

• B. Bauer, X. Cai, S. Peth, K. Schladitz, and G. Steidl. Variational-based Segmentation of Biopores in Tomographic Images. Computers & Geosciences, 98:1–8, 2017.

• J. Lee, X. Cai, M. Dalponte, Y. Malhi, N. Butt, M. Morecroft, C.-B. Schonliev, and D. Cooms. Individual Tree Species Classification from Airborne Multisensor Imagery Using Robust PCA. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 9(6):2554–2667, 2016.

• X. Cai, C.B. Schonlieb, J. Lee, J. Scaife, K. Harrison, M. Sutcliffe, M. Parker and N. Burnet. Automatic Contouring of Soft Organs for Image-guided Prostate Radiotherapy. Radiother Oncol., 119 (suppl 1):S895–896, 2016.

• J. Lee, X. Cai, C.-B. Schonlieb, and D. Coomes. Non-parametric Image Registration of Airborne LiDAR, Hyperspectral and Photographic Imagery of Wooded Landscapes. IEEE Transactions on Geoscience and Remote Sensing, 99:1–12, 2015.

• J. Lee, X. Cai, C.-B. Schonlieb, and D. Coomes. Mapping Individual Trees from Airborne Multi- sensor Imagery. International Geoscience and Remote Sensing Symposium (IGRSS), IEEE Geoscience and Remote Sensing Society, 2015.

• J. Scaife, K. Harrison, A. Drew, X. Cai, et al. Accuracy of Manual and Automated Rectal Contours Using Helical Tomotherapy Image Guidance Scans during Prostate Radiotherapy. J. Clin. Oncol., 33:94–94, 2015.

• X. Cai. Variational Image Segmentation Model Coupled with Image Restoration Achievements. Pattern Recognition, 48:2029–2042, 2015.

• X. Cai, J. Fitschen, M. Nikolova, G. Steidl, and M. Storath. Disparity and Optical Flow Partitioning Using Extended Potts Priors. Information and Inference: A Journal of the IMA, 4(1):43–62, 2015.

• X. Cai and G. Steidl. Multiclass Segmentation by Iterated ROF Thresholding. EMMCVPR(2013), Lecture Notes in Computer Science, 8081:237–250, Springer, 2013.

• X. Cai, R. Chan, S. Morigi, and F. Sgallari. Vessel Segmentation in Medical Imaging Using a Tight-Frame Based Algorithm. SIAM Journal on Imaging Sciences, 6(1):464–486, 2013.

• X. Cai, R. Chan, and T. Zeng. A Two-Stage Image Segmentation Method Using a Convex Variant of the Mumford-Shah Model and Thresholding. SIAM Journal on Imaging Sciences, 6(1):368–390, 2013.

• X. Cai, R. Chan, Serena Morigi, and Fiorella Sgallari. Framelet-Based Algorithm for Segmentation of Tubular Structures. SSVM(2011), Lecture Notes in Computer Science, 6667:411–422, Springer, 2012.