Color Science Seminar: UStress: a new fidelity measure between computed image quality and observers quality scores

Color Science Seminar
UStress: a new fidelity measure between computed image quality and observers quality scores

Dr. Samuel Morillas Gómez
Professor, Higher Technical School of Computer Engineering
Polytechnic University of Valencia

Abstract:
Assessment of the visual quality of colour images is usually a difficult process, validated through hard-to-carry-out psychophysical experiments, used to record observer quality scores. Visual image quality metrics aim to maximise the agreement between computed indexes and observer scores, or opinions. Therefore, in this area, it is of critical importance to have appropriate measures of this agreement (i.e. performance) between the computed image quality metric values and observer’s quality scores, both for the development, as well as for the use of image quality metrics. Among the measures of agreement, the most used one nowadays is the well-known Pearson correlation coefficient, while Spearman rank correlation coefficient is also commonly used. The aim of this paper is two-fold. First, to introduce the Standardized Residual Sum of Squares as an alternative metric for the agreement between computed image quality and observers quality scores and analyse its properties and advantages in front of Pearson, Spearman and Kendall correlation coefficients; Second, to introduce a new version that takes observers’ scores variability into account. The results on synthetic and real datasets support that has a series of benefits in front of the classical approaches and that the inclusion of uncertainty in has an important effect on the results, quantified by statistical significance tests. A free to download MATLAB code version of is available at https://viplab.webs.upv.es/resources/

Speaker Bio:
Prof. Samuel Morillas has a BSc in Computer Science from Unvieridad de Granada and a PhD in Applied Mathematics from Universitat Politècnica de València (UPV) in Spain. From 2019 he is a full professor of the Applied Math department at UPV, where he is a member of the Instituto of Pure and Applied Math. His undergraduate teaching includes fundamental algebra and calculus for first-year students and Continuous modeling for the 3rd year students of the Data Science degree. His graduate teaching at UPV concerns fuzzy logic and applications. He has also been an invited professor in a series of Universities: University of Granada (Spain), Rochester Institute of Technology (NY, USA), Chonbuk National University (South Korea), University at Buffalo (NY, USA), Colorado University at Boulder (Co, USA), Harvard University (Massachusetts, USA), University of Edinburgh (UK) and Metropolia University of Applied Sciences (Finland), where he has taught different courses and seminars about fuzzy logic, image processing, and image appearance models.His research has been focused on fuzzy logic and fuzzy metrics both in the theoretical field and, mostly, in their applications. He has developed different solutions based on fuzzy logic and fuzzy metrics for problems in different fields including image processing, color science, and pavement engineering. He has published more than 50 papers in scientific journals and presented more than 70 contributions to scientific conferences.

Intended Audience:
All are Welcome!

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