Thrasos Pappas

Visual Signal Analysis and Compression: Focus on Texture

Thrasos Pappas
October 27, 2010

Open video link.

Abstract: The fields of visual signal analysis and compression have made significant advances during the last two decades, incorporating sophisticated signal processing techniques and models of human perception.

One of the keys to further advances is a better understanding of texture.  We examine a number of applications that critically depend on texture analysis, including image and video compression, computer vision, content-based retrieval, visual to tactile image conversion, and multimodal interfaces.   We introduce the idea of "structurally lossless" compression of visual data that allows significant differences between the original and decoded images, which may be perceptible when they are viewed side-by-side, but do not affect the overall quality of the image.  We then discuss the development of objective texture similarity metrics, which allow substantial point-by-point deviations between textures that according to human judgment are essentially identical.

BIOGRAPHY: Thrasos Pappas received the Ph.D. degree in electrical engineering and computer science from MIT in 1987.  From 1987 until 1999, he was a Member of the Technical Staff at Bell Laboratories, Murray Hill, NJ. He joined the EECS Department at Northwestern 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 is a Fellow of the IEEE and SPIE. He is currently editor-in-chief of the IEEE Transactions on Image Processing.   He has served as an elected member of the Board of Governors of the Signal Processing Society of IEEE (2004-2007), chair of the IEEE Image and Multidimensional Signal Processing Technical Committee (2002-2003), and technical program co-chair of ICIP-01 and ICIP-09.  Since 1997 he has been co-chair of the SPIE/IS&T Conference on Human Vision and Electronic Imaging.