Dr Charith Abhayaratne
PhD
School of Electrical and Electronic Engineering
Senior Lecturer
Full contact details
School of Electrical and Electronic Engineering
Sir Frederick Mappin Building
Mappin Street
Sheffield
S1 3JD
- Profile
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I received the B.E. degree in electrical and electronic engineering from The University of Adelaide, Australia, in 1998, and the PhD. degree in electronic and electrical engineering from the University of Bath, U.K., in 2002. I am a recipient of the Alain Bensoussan Fellowship awarded by the European Research Consortium for Informatics and Mathematics (ERCIM) to carry out postdoctoral research at the Centre of Mathematics and Computer Science (CWI), The Netherlands (2002), and the National Research Institute for Computer Science and Control (INRIA), Sophia Antipolis, France (2003). During the fellowship, my research was on adaptive wavelet transforms for image and video coding and analysis. After the fellowship, I was a postdoctoral research associate at Queen Mary, University of London, where I worked on wavelet based scalable video coding research. In 2005, I joined the University of Sheffield as a lecturer.
My research is focused on signal processing and machine learning for multimedia security, automated understanding of visual content (computer vision) and video coding. I lead a group of researchers working on these topics. In terms of multimedia security, I am working on methodologies for robust and imperceptible data hiding and exploring block-chain technology for multimedia content tracking and protection. In terms of visual content understanding, my current work is on understanding and modelling of visual salience in the context of robotic and UAV applications, automated recognition of human activities of daily living in the context of assisted living and modelling of complex 2D and 3D shapes leading to real time number and object recognition. In terms of video coding, current research includes coding of high dynamic range (HDR) video, ultra high definition (UHD) video and 360 degrees video. Current and recently concluded research has been funded by Innovate UK, EPSRC and Industry sponsors.
Currently, I serve as an associate editor for IEEE Transactions in Image Processing, IEEE Access and Elsevier Journal of Information Security and Applications (JISA) and I have served as a guest editor for Signal Processing: Image Communication (in 2009). At present, I am serving as a member of the EPSRC peer review college, a committee member of the British Standards Institution (BSI) group IST/037 coding of picture, audio, multimedia and hypermedia information and a member of Multimedia Security and Forensics Technical Committee of Asia-Pacific Signal and Information Processing Association (APSIPA). I have served as the UK Liaison for the European Association for Signal Processing (EURASIP) and a member of the IEEE Multimedia Communications technical committee from 2010-2019. In 2004-2006, I have contributed to the development of the scalable video standardisation and wavelet video exploration activities within the ISO/IEC Moving Picture Expert Group (MPEG).
- Research interests
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- AI and machine learning for computer vision.
- AI and machine learning for multimedia security and forensics.
- Multi-modal sensing, data analysis and machine learning.
- Signal, image, video and graph processing and analysis.
- Video and image coding, streaming and visual quality metrics.
- Applications in robotics, creative industries, security and surveillance, assisted living, healthcare, remote sensing, sports visual analysis, computational imaging, digital manufacturing and international standards (JPEG and MPEG).
- Publications
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Journal articles
- Region-CAM: Toward Accurate Object Regions in Class Activation Maps for Weakly Supervised Learning Tasks. IEEE Access, 13, 208361-208375.
- Spatio-temporal graph neural network based child action recognition using data-efficient methods: A systematic analysis. Computer Vision and Image Understanding, 259. View this article in WRRO
- On the Adversarial Robustness of Hand-Crafted Features and Their Role in Defending Adversarial Examples. IEEE Access, 1-1.
- An Approximate Computing-Based Spiking Neural Networks Neuron Model and STDP Learning. IEEE Transactions on Circuits and Systems I: Regular Papers, 1-14.
- Region-of-interest aware 3D ResNet for classification of COVID-19 chest computerised tomography scans. IEEE Access, 11, 28856-28872.
Conference proceedings
- Is Structural Awareness the Key to Event Camera Data Cleansing for Enhancing Veracity?. The 36th British Machine Vision Conference
- A High Accuracy and Hardware Efficient Approximate Computing based Leaky integrate-and-fire Neuron Model. 2025 IEEE 38th International System-on-Chip Conference (SOCC) (pp 1-6), 29 September 2025 - 1 October 2025.
- Weakly-supervised localization of manipulated image regions using multi-resolution learned features.. BMVC Workshop proceedings. Glasgow, UK, 25 November 2024 - 25 November 2024. View this article in WRRO
- WCBnet: Weighted convolutional block modelling of signed-value error levels for image-wise copy-move and splicing detection. 2023 IEEE 25th International Workshop on Multimedia Signal Processing (MMSP) Proceedings. Poitiers, France, 27 September 2023 - 27 September 2023. View this article in WRRO
- SSDB-Net: a single-step dual branch network for weakly supervised semantic segmentation of food images. 2023 IEEE 25th International Workshop on Multimedia Signal Processing (MMSP) Proceedings. Poitiers, France, 27 September 2023 - 27 September 2023. View this article in WRRO
- TRAIT: A trusted media distribution framework. 2023 24th International Conference on Digital Signal Processing (DSP). Island of Rhodes, Greece, 11 June 2023 - 11 June 2023. View this article in WRRO
- Exploration of verbal descriptions and dynamic indoors environments for people with sight loss. CHI '23: Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems (pp 110). Hamburg, Germany, 23 April 2023 - 23 April 2023. View this article in WRRO
- AW-GATCN: Adaptive Weighted Graph Attention Convolutional Network for Event Camera Data Joint Denoising and Object Recognition. Proceedings of 2025 International Joint Conference on Neural Networks (IJCNN). Rome, Italy, 30 June 2025 - 30 June 2025.
Preprints
- Weakly-supervised Localization of Manipulated Image Regions Using Multi-resolution Learned Features..
- AW-GATCN: Adaptive Weighted Graph Attention Convolutional Network for Event Camera Data Joint Denoising and Object Recognition, arXiv.
- NLS: Natural-Level Synthesis for Hardware Implementation Through GenAI..
- NLS: Natural-Level Synthesis for Hardware Implementation Through GenAI, arXiv.
- Region-CAM: Toward Accurate Object Regions in Class Activation Maps for Weakly Supervised Learning Tasks. IEEE Access, 13, 208361-208375.