Edinburgh Napier University

  Video communication systems for deaf people are limited in terms of quality and performance. Analysis of visual attention mechanisms for sign language may enable optimization of video coding systems for deaf users. Eye-movement tracking experiments were conducted with profoundly deaf volunteers while watching sign language video clips. Deaf people are found to fixate mostly on the facial region of the signer to pick up small detailed movements associated with facial expression and mouth shapes. Lower resolution, peripheral vision is used to process information from larger, rapid movements of the signer in the video clips. A coding scheme that gives priority to the face of the signer may be applied to improve perception of video quality for sign language communication.

Visual perception is the process of acquiring knowledge about environmental objects and events by extracting information from the light they emit or reflect (Palmer, 2002). How we “see” remains an active research challenge for vision scientists and specialists. Understanding the detection, recognition, and interpretation of visual information could have a tremendous impact on how we present and use visual information and on the design of information systems. The challenge is to understand how visual information can be presented so that its use can be optimized for the observer.

Of all the senses, vision is relied on most heavily for sensory input about the environment (Hendee & Wells, 1997). This is particularly true for deaf people who rely on visual communication of information using sign language and/or lip reading. The aim of this research is to investigate how deaf people see sign language. The rationale for this is that an understanding of how deaf people observe sign language could enable video communication systems, for example, video conferencing, to be optimized.

In this study, we examine the influence of sign language video content on the attention mechanisms of deaf viewers and the implications for design of video communications systems for deaf people. We review the quality requirements for sign language video communication and what is known about scene perception and the eye gaze of deaf people observing sign language. An experiment is presented, using eye tracking, to investigate how deaf people perceive sign language video and this is discussed in the context of improving sign language video communication quality.