Perceptual Compression and Eye-tracking Lab
Department of Computer Science, Kent State University


Perceptual Media Compression for Multiple Viewers with Feedback Delay




Oleg Komogortsev,  Javed I. Khan
 Perceptual Compression and Eye-tracking Lab
Department of Computer Science
Kent State University
, 233 MSB, Kent, OH 44242

Last Revised March 25, 2006





Human eyes have limited perception capabilities. Only 2 degrees of our 180 degree vision field provide the highest quality of perception. Due to this fact the idea of perceptual attention focus emerged to allow a visual content to be changed in a way that only part of the visual field where a human attention is directed to is encoded with a high quality. The image quality in the periphery can be reduced without a viewer noticing it. This compression approach allows a significant decrease in bit-rate for a video stream, and in the case of the 3D stream rendering, it decreases the computational burden.  A number of previous researchers have investigated the topic of real-time perceptual attention focus but only for a single viewer. In this paper we investigate a dynamically changing multi-viewer scenario. In this type of scenario a number of people are watching the same visual content at the same time. Each person is using eye-tracking equipment. The visual content (video, 3D stream) is sent through a network with a large transmission delay. The area of the perceptual attention focus is predicted for the viewers to compensate for the delay value and identify the area of the image which requires highest quality coding.

Keywords: Perceptual compression, visual media adaptation. 

This report contains experiment clips used to test the performance of this system.  The videos are MPEG-2 ISO 13818-2 streams. We recommend using MPlayer found at or Winamp to view these video samples.



Original Video Samples:






     One viewer is wearing eye-tracking equipments ASL 501 and watching Shamu video:



 3 viewers are watching Shamu video together. Saccade Windows are constructed. Eye-gazes are displayed:



      Optimal Perceptual Attention Set (OPAF) compared to Saccade Windows Union (USW) for Shamu video:


     OPAF set has green border and USW has pink border