S3P 2015 Tutorial 3

Visual Perception Models and Metrics, Prof. Sheila Hemami, Northeastern University of Boston (US) and Prof. Thrasyvoulos Pappas, Northwestern University (US)


We will examine objective criteria for the evaluation of image quality that are based on models of visual perception.  Our primary emphasis will be on image fidelity, i.e., how close an image is to a given original or reference image, but we will broaden the scope of image fidelity to include structural equivalence.  We will also discuss no-reference and limited-reference metrics.  We will examine a variety of applications with special emphasis on image and video compression.  We will examine near-threshold perceptual metrics, which explicitly account for human visual system (HVS) sensitivity to noise by estimating thresholds above which the distortion is just-noticeable, and supra-threshold metrics, which attempt to quantify visible distortions encountered in high compression applications or when there are losses due to channel conditions.  We will also consider metrics for structural equivalence, whereby the original and the distorted image have visible differences but both look natural and are of equally high visual quality.  We will also take a close look at procedures for evaluating the performance of quality metrics, including database design, models for generating realistic distortions for various applications, and subjective procedures for metric development and testing.  Throughout the course we will discuss both the state of the art and directions for future research.


photo_pappas.jpgTHRASYVOULOS N. PAPPAS received the S.B., S.M., and Ph.D. degrees in electrical engineering and computer science from MIT in 1979, 1982, and 1987, respectively.  From 1987 until 1999, he was a Member of the Technical Staff at Bell Laboratories, Murray Hill, NJ.  He is currently a professor in the Department of Electrical and Computer Engineering at Northwestern University, which he joined in 1999.  His research interests are in image and video quality and compression, image and video analysis, content-based retrieval, perceptual models for multimedia processing, model-based halftoning, and tactile and multimodal interfaces.  Prof. Pappas has served as co-chair of the 2005 SPIE/IS&T Electronic Imaging Symposium, and since 1997 he has been co-chair of the SPIE/IS&T Conference on Human Vision and Electronic Imaging. Dr. Pappas is a Fellow of IEEE and SPIE.  He has also served as editor-in-chief of the IEEE Transactions on Image Processing (2010-12), elected member of the Board of Governors of the Signal Processing Society of IEEE (2004-06), chair of the IEEE Image and Multidimensional Signal Processing (now IVMSP) Technical Committee, technical program co-chair of ICIP-01 and ICIP-09, and co-chair of the 2011 IEEE IVMSP Workshop on Perception and Visual Analysis.  He has also served on the editorial boards of the IEEE Transactions on Image Processing, the IEEE Signal Processing Magazine, the Journal of Electronic Imaging, and the Foundations and Trends in Signal Processing.

SheilaHighres.jpegSHEILA S. HEMAMI received the B.S.E.E. degree from the University of Michigan in 1990, and the M.S.E.E. and Ph.D. degrees from Stanford University in 1992 and 1994, respectively. She was with Hewlett-Packard Laboratories in Palo Alto, California in 1994 and was with the School of Electrical Engineering at Cornell University from 1995-2013.  She is currently Professor and Chair of the Department of Electrical & Computer Engineering at Northeastern University in Boston, MA. Dr. Hemami's research interests broadly concern communication of visual information from the perspectives of both signal processing and psychophysics. She was elected a Fellow of the IEEE in 2009 for her for contributions to robust and perceptual image and video communications. Dr. Hemami has held various visiting positions, most recently at the University of Nantes, France and at Ecole Polytechnique Federale de Lausanne, Switzerland. She has received numerous university and national teaching awards, including Eta Kappa Nu's C. Holmes MacDonald Award. She was a Distinguished Lecturer for the IEEE Signal Processing Society in 2010-11, was editor-in-chief for the IEEE Transactions on Multimedia from 2008-10.  She has held various technical leadership positions in the IEEE.