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IMAGE QUALITY METRICS FOR VOLUMETRIC LASER DISPLAYSRodney Don Williams and Daniel DonohooTexas Instruments IncorporatedComputer Systems LaboratoryUser Systems Engineering LaboratoryDallas, Texas, USAABSTRACTThis paper addresses the extensions to the image quality metrics and related human factors research that are needed to establish thebaseline standards for emerging volume display technologies. The existing and recently developed technologies for multiplanarvolume displays are reviewed with an emphasis on basic human visual issues. Human factors image quality metrics and guidelinesareneeded to firmly establish this technology inthe marketplace. Thehuman visualrequirements and the display designtradeoffs forthese prototype laser-based volume displays are addressed and several criticalimage quality issues identified for further research. TheAmerican National Standard for Human Factors Engineering ofVisual Display Terminal Workstations (ANSI HFS-100) and otherintemationalstandards (ISO, DIN) can serve as a starting point, butthis researchbase mustbe extended to providenew image qualitymetrics for this new technology for volume displays.1. INTRODUCTIONThis paper provides an overview of volumetric display technology and presents the human factors research needed for effectivevolumetric information displays. Texas Instruments has developed an autostereoscopic multiplanar volume display technology overthe last 4 ars' During the development of this technology, we conducted an extensive review of previous technologies for truevolume displays and identified numerous research issues associated with volume technology. The American National Standard forHuman Factors Engineering of Visual Display Terminal Workstations can serve as a starting point, but this research base must beextended to provide the image quality metrics for volume displays.or as a physical 3-D volume as described herein. For some tasks, the parallax cues from stereoscopic presentations are sufficient.However, for many multiple-person (team) tasks where numerous views are required, a true volume display is preferred. This articlereviews the various technologies for implementing these volume displays and the image quality issues associated withthis emergingtechnology.In this context, the term "volumetric display" refers to a display device that uses a physical volume to present images having height,depth, and width. These images occupy physical space and are not a 2-D rendering of a 3-D image. A "voxel" is a volume displaypicture element(pixel)having a physical X, Y, and Z dimensionality in a specific location in a volume display. Note that these termsare often used to describe a virtual 2-D display with additional 3-D cues such as parallax, perspective, etc. However, for the purposeof this paper, I am referring to an actual physical volume of three dimensions.While the human visual system was created to effectively perceive and comprehend the world in a full three dimensions, currentcomputer graphics displays provide only 2-D views of the real world. This incompatibility becomes most pronounced when a useris asked to monitor and control the relative position of objects in a volume of space. We need information displays that bettercommunicate the relative position of 3-D objects in real space and provide complete visual cues.Current 2-D perspective displays have limitations when used for dynamic volumetric tasks such as battle management and air

The work reported systematically examined four types of formatting (vertical, compact, chunk extended, and message extended), three levels of message load (two, four, and six units), four methods of sequencing (chunk, line, words, and unsequenced) and three presentation rates (0.25, 0.5, and 1. 00 sec/word). The first study was a repeated-measures design, in which 32 subjects were given all combinations of format and sequencing. From this initial study, one combination of format and sequence was selected for further study. The second study examined the compact chunk presentation for the three levels of message load and for three exposure rates. Recommendations are made for the optimal dynamic presentation of messages on computer-generated displays given limited viewing time. The examples considered here simulate the kinds of real-time messages flashed alongside highways to inform motorists of traffic situations ahead and to give directions for alternate routing.

This article reviews the various methods for specifying the user-system interface (USI). Systematic procedures for developing and specifying USI requirements are presented. The use of requirements specification is traced through the stages in the design with recommendations for the efficient communication of user-system requirements. Consideration is given to the specification of the dynamics of the system operations as they impact the user-system interface. The use of a User System Interface Design Document (USIDD) is recommended and a suggested format is given.