Sophie Triantaphillidou

About

Sophie Triantaphillidou is an Adjunct Professor in the Department of Computer Science at NTNU in Gjøvik Norway and a memeber of the Norwegian Colour and Visual Computing Laboratory (Coloulab). She has a BSc in Photographic and Electronic Imaging Science and a PhD in Imaging Science (in collaboration with the Royal Photographic Society) both from the Unversity of Westminster, UK.

Prior to joining NTNU she had a 27-year career at the University of Westminster where she taught, let academic programmes in imaging and colour science, supervised graduate students and managed research projects, and where she currently holds a Honorary Professorship. Her research focuses on imaging system performance, image quality and applied human vision.

Research

Sophie Triantaphillidou's research is on the intersection between imaging system performance, image quality and perception by humans and computer vision systems. She has academic and industry funded research, including collaborations with the Home Office on and Ministry of Defence in UK, Nokia UK, Huawei China, Nvidia USA and a number of start-ups. Current research interests include i) use of comutational means for deriving imaging system performance direcrly from pictorial images and eliminate the need of test chats and lab conditions, ii) image representation, information and image quality in relation to neural network performance.

Norwegian Colour and Visual Computing Laboratory (Colourlab)

Publications

The Manual of Photography, 10th edition, Focal Press (Elsevier)

The Manual of Photography is a classical book (1st edition, 1890) presenting the underlying scientific principles of photography and digital imaging - for professional photographers, researchers, lab technicians, students and enthusiastic amateurs.

Plavac, N., Amirshahi, S. A., Pedersen, M. and Triantaphillidou S. (2024), The Influence of Read Noise on Automatic License Plate Recognition, accepted IS&T London Imaging Meeting 2024.

Psarrou, A., Triantaphillidou, S., Feisal, I. and van Zwanenberg, O. (2023), A framework for the metrification of input image quality in deep networks, in Electronic Imaging 2023, pp 307-1 - 307-7, https://doi.org/10.2352/EI.2023.35.8.IQSP-307

van Zwanenberg, O., Triantaphillidou, S. and Jenkin, R. (2023), A tool for deriving camera spatial frequency response from natural scenes (NS-SFR), in Electronic Imaging, pp311-1-311-6, doi.org/10.2352/EI.2023.35.8.IQSP-311

Jarvis, J., Triantaphillidou, S. and Gupta, G. (2022), Contrast discrimination in images of natural scenes, Journal of the Optical Society of America A. 39 (6), pp. B50-B64, https://doi.org/10.1364/JOSAA.447390

van Zwanenberg, O., Triantaphillidou, S., Jenkin, R. and Psarrou, A. (2021), Estimation of ISO12233 Edge Spatial Frequency Response from Natural Scene Derived Step-Edge Data, Journal of Imaging Science and Technology, 65 (6), pp. 60402-1-60402-16. https://doi.org/10.2352/j.imagingsci.technol.2021.65.6.060402

van Zwanenberg, O., Triantaphillidou, S., Psarrou, A. and Jenkin, R, (2021), Analysis of Natural Scene Derived Spatial Frequency Responses for Estimating Camera ISO12233 Slanted-edge Performance, Journal of Imaging Science and Technology, 65 (6), pp 60405-1 – 60405-12. https://doi.org/10.2352/j.imagingsci.technol.2021.65.6.060405

van Zwanenberg, O., Triantaphillidou, S., Jenkin, R. and Psarrou, A. (2021), Natural Scene Derived Camera Edge Spatial Frequency Response for Autonomous Vision Systems, IS&T London Imaging Meeting 2021, https://doi.org/10.2352/issn.2694-118X.2021.LIM-88

Triantaphillidou, S., Smejkal, J., Fry E. W. S., Hung C. H. (2020), Studies on the effect of MegaPixel sensor resolution on displayed image quality and relevant metrics, IS&T Electronic Imaging Symposium: Image Quality & System Performance conference, San Francisco, California, USA, https://doi.org/10.2352/ISSN.2470-1173.2020.9.IQSP-170

van Zwanenberg, O., Triantaphillidou, S., Jenkin, R. and Psarrou, A. (2020), Camera System Performance Derived from Natural Sciences, IS&T Electronic Imaging Symposium: Image Quality & System Performance conference, San Francisco, California, USA.(Best conference paper award), https://doi.org/10.2352/ISSN.2470-1173.2020.9.IQSP-241

Fry, E. W. S., Triantaphillidou, S., Jenkin, R. B., Jacobson, R. E. and Jarvis, J. R. (2020), Noise Power Spectrum Scene-Dependency in Simulated Image Capture Systems, In: IS&T Electronic Imaging Symposium: Image Quality & System Performance conference, San Francisco, California, USA, https://doi.org/10.2352/ISSN.2470-1173.2020.9.IQSP-345

Fry, E. W. S., Triantaphillidou, S., Jenkin, R. B., Jacobson, R. E. and Jarvis, J. R. (2019), Scene-and-Process-Dependent Spatial Image Quality Metrics, Journal of Imaging Science & Technology, 9, 60407-1-60407-13, https://doi.org/10.2352/J.ImagingSci.Technol.2019.63.6.060407

Fry, E. W. S., Triantaphillidou, S., Jenkin, R. B., Jacobson, R. E. and Jarvis, J. R. (2019), Validation of Modulation Transfer Functions and Noise Power Spectra from natural scenes, Journal of Imaging Science & Technology, 9, 60406-1-60406-11, https://doi.org/10.2352/J.ImagingSci.Technol.2019.63.6.060406

Van Zwanenberg, O., Triantaphillidou, S., Jenkin, R. and Psarrou, A. (2019), Edge detection techniques for quantifying spatial imaging system performance and image quality, ACM/IEEE Conference on Computer Vision and Pattern Recognition (IEEE/ CFV CVPR 2019).Long Beach, California 15 – 21 Jun 2019, https://doi.org/10.1109/CVPRW.2019.00238

Triantaphillidou, S., Jarvis, J. R., Psarrou, A. and Gupta, G. (2019) Contrast sensitivity in images of natural scenes, Signal Process Image, Signal Processing: Image Communication, 75, pp. 64-75, https://doi.org/10.1016/j.image.2019.03.002

Triantaphillidou, S., Fry, E., Sanchis, V. and Pons, A. (2018) Image Quality Loss and Compensation for Visually Impaired Observers. In: IS&T Electronic Imaging Symposium: Human Vision & Electronic Imaging conference, San Francisco, California, USA, https://doi.org/10.2352/issn.2470-1173.2018.12.iqsp-365

Fry, E., Triantaphillidou, S., Jacobson, R., Jarvis, J. and Jenkin, R. B. (2018), Bridging the Gap Between Imaging Performance and Image Quality Measures. In: IS&T Electronic Imaging Symposium 2018 – Image Quality System Performance XV, San Francisco, CA, USA. (Best student paper award), https://doi.org/10.2352/ISSN.2470-1173.2018.12.IQSP-231

Branca, R., Triantaphillidou, S. and Burns, P.D. (2017), Texture MTF from images of natural scenes. In: Electronic Imaging: Image Quality and System Performance XIV, 29 Jan 2017 to end of 02 Feb 2017, San Francisco, California, USA, https://doi.org/10.2352/ISSN.2470-1173.2017.12.IQSP-255

Tsifouti A, Triantaphillidou S., Larabi M-C, Bilissi E. and Psarrou A. (2015), A case study in identifying acceptable bitrates for human face recognition tasks, Signal Processing: Image Communication, 36, 14, https://doi.org/10.1016/j.image.2015.05.002

Tsifouti A, Triantaphillidou S., Larabi M-C, Bilissi E. and Psarrou A. (2015), The effects of scene content parameters, compression, and frame rate on the performance of analytics systems, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XII, V.9396, 93960X, https://doi.org/10.1117/12.2083426

Fry E., Triantaphillidou S., Jarvis J. and Gupta G. (2015), Image quality optimization, via application of contextual contrast sensitivity and discrimination functions, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XII, V.9396, 93960K, https://doi.org/10.1117/12.2082937

Tsifouti A, Triantaphillidou S., Larabi M-C, Bilissi E. and Psarrou A. (2015), Comparative performance between human and automated face recognition systems, using CCTV imagery, different compression levels and scene parameters, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XII, V.9396, 93960M, https://doi.org/10.1117/12.2083325

Park J.Y., Triantaphillidou S. and Jacobson R.E. (2014), Just noticeable differences in perceived image contrast with changes in displayed image size, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XI, V.9016, 8621oB, https://doi.org/10.1117/12.2042534

Allen E., Triantaphillidou S. and Jacobson R.E. (2014), Perceptibility and acceptability of JPEG 2000 compressed images of various scene types, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XI, V.9016, 90160W, https://doi.org/10.1117/12.2042582

Triantaphillidou S, Jarvis J. and Gupta G. (2014) Spatial contrast sensitivity and discrimination in pictorial images, Proc. IS&T/SPIE Electronic Imaging: Image Quality & System Performance XI, V.9016, 86111A, https://doi.org/10.1117/12.2040007

Triantaphillidou S., Jarvis J., Gupta G. and Rana H. (2013) Defining human contrast sensitivity and discrimination from complex imagery,Proc. SPIE 8901 Optics and Photonics for Counterterrorism, Crime Fighting and Defence IX; and Optical Materials and Biomaterials in Security and Defense Systems Technology X, 89010C, https://doi.org/10.1117/12.2029194

Triantaphillidou S, Jarvis J. and Gupta G. (2013) Contrast sensitivity and discrimination of complex scenes, Proc. IS&T/SPIE 8653 Electronic Imaging: Image Quality & System Performance X, 86530C, https://doi.org/10.1117/12.2006076

Tsifouti A., Triantaphilldou S., Bilissi E. and Larabi M.C. (2013) Acceptable compression levels for human face recognition from CCTV imagery, Proc. IS&T/SPIE 8653 Electronic Imaging: Image Quality & System Performance X, 865305, (Best student paper award), https://doi.org/10.1117/12.2004140

Gupta G., Psarrou A., Triantaphillidou S. and Park J.Y. (2012) Visual scene busyness measures through a region growing spatial segmentation, Proc. SPIE 8546, Optics and Photonics for Counterterrorism, Crime Fighting, and Defence VIII, 85460P, https://doi.org/10.1117/12.974760

Park J.Y., Triantaphillidou S., Jacobson R.E. and Gupta G. (2012) Evaluation of perceived image sharpness with changes in the displayed image size, Proc. IS&T/SPIE 8293 Electronic Imaging: Image Quality & System Performance IX, 82930J, https://doi.org/10.1117/12.908201

Oh K.H., Triantaphillidou S. and Jacobson R.E. (2011) Device independent, scene dependent image quality predictions, Proc. IS&T/SPIE7867 Electronic Imaging: Image Quality & System Performance VIII, 78670R, https://doi.org/10.1117/12.871986

Oh K.H., Triantaphillidou S. and Jacobson R.E., Scene classification with respect to image quality measurements, Proc. IS&T/SPIE 7529 Electronic Imaging: Image Quality & System Performance V, 752908, https://doi.org/10.1117/12.838302

Mancusi F., Triantaphillidou S. and Allen E. (2010) Multidimensional image selection and classification system based on visual feature extraction and scaling, Proc. IS&T/SPIE 7529 Electronic Imaging: Image Quality & System Performance V, 75290A, https://doi.org/10.1117/12.838734

Park J.Y., Triantaphillidou S. and Jacobson R.E. (2009) Identification of image attributes that are most affected with changes in displayed image size, Proc. IS&T/SPIE 7243 Electronic Imaging Image Quality & System Performance V, 724210, https://doi.org/10.1117/12.805844

Oh K. H., Triantaphillidou S. and Jacobson R.E. (2009) Perceptual image attribute scales derived from overall image quality assessments, Proc. IS&T/SPIE 7242 Electronic Imaging: Image Quality & System Performance V, 722420C, https://doi.org/10.1117/12.805848

Attridge G.G., Vagal G., Triantaphillidou S. and Pointer M. R. (2008) Subjective and objective measures of colour hard copy images, The Imaging Science Journal, 56, 163, https://doi.org/10.1179/174313108X281326

Orfanidou M., Triantaphillidou S. and Allen E. (2008) Predicting Compressed Image Quality Using a Modular Image Difference Model, Proc. IS&T/SPIE 6808 Electronic Imaging: Image Quality & System Performance V, 68080F, https://doi.org/10.1117/12.766407

Smith R., Brown K., Tighe J.F., Cohen N., Triantaphillidou S. and Macdonald L.W. (2008) Colour Analysis and Verification of CCTV images under different lighting conditions, Proc. IS&T/SPIE 6808 Electronic Imaging: Image Quality & System Performance V, 68080Y, https://doi.org/10.1117/12.766343

Allen E., Triantaphillidou S., and Jacobson R.E. (2007) Image Quality Comparison Between JPEG and JPEG2000. I. Psychophysical Measurements, Journal of Imaging Science & Technology 51, 248, https://doi.org/10.2352/J.ImagingSci.Technol.(2007)51:3(248)

Triantaphillidou S., Allen E. and Jacobson R.E. (2007) Image Quality Comparison Between JPEG and JPEG2000. II. Scene Dependency, Scene Analysis, and Classification, Journal of Imaging Science & Technology, 51, 259, https://doi.org/10.2352/J.ImagingSci.Technol.(2007)51:3(259)

Jenkin R.B., Triantaphillidou S. and Richardson M. A. (2007) Effective Pictorial Information Capacity as an Image Quality Metric, Proc. IS&T/SPIE 6494 Electronic Imaging: Image Quality & System Performance IV, 64940O, https://doi.org/10.1117/12.703973

Triantaphillidou S. and Jacobson R.E. (2004) Measurements of the Modulation Transfer Function of Image Displays, Journal of Imaging Science and Technology, 48, 58,

Triantaphillidou S., Jacobson R.E. and Attridge G.G. (2002) A Case Study in the Digitisation of a Photographic Collection, The Imaging Science Journal, 50, 97.

Jacobson R.E. and Triantaphillidou S. (2002) Metric Approaches to Image Quality, In book ‘Colour Science: Exploiting Digital Media’, Editors L. MacDonald and R. Luo, John Wiley & Sons, Chichester, UK, Chapter 18, 371.

Triantaphillidou S. (2001) Image Quality in the Digitisation of Photographic Collections, PhD thesis, University of Westminster, UK.

Triantaphillidou S. and Jacobson R.E. (2001) A Simple Approach to Digitising a Photographic Collection, Proc. IS&T PICS 2001, 160.

Triantaphillidou S. and Jacobson R.E. (2000) A Simple Method for the Measurement of Modulation Transfer Functions of Displays, Proc. IS&T PICS 2000, 231.

Triantaphillidou S., Jacobson R.E. and Fagard-Jenkin R.B. (1999) An Evaluation of MTF Determination Methods for 35mm Film Scanners, Proc. IS&T PICS 1999, 231.

Triantaphillidou S., Jacobson R.E. and Ford A.M. (1998) Preferred Tone Reproduction of Images on Soft Displays, Proc. ICPS, Vol. 2. Track 3: Electronic Imaging, 204.

Språkvelger

Sophie Triantaphillidou