Ribera

Ribera, Extending Image Quality Metrics to Head-Mounted Displays

Abstract

The wide field of view in head-mounted displays implies that most of the content shown by the display appears at high eccentricities. However, most image quality metrics assume that the image is viewed by the fovea, where the human visual system presents its highest acuity. In this project, we extend an image quality metric based on ISETBIO to wide field of views. We apply publicly available measurements of the Optical Transfer Function of the human cornea and lens at different eccentricities. In this manner, our Delta E error map becomes eccentricity-dependent. After incorporating more accurate OTF models to our method, we expect to use this image quality metric as a tool to design newer displays technologies that take advantage of the loss of acuity in higher eccentricities.

Introduction

Head-mounted displays are pushing the display specifications (e.g, resolution or refresh rate) much beyond those of traditional displays. One of the reasons is the need to cover a huge field of view with a higher pixel density, since the resolvable pixel size at such close distances is much smaller. This unavoidably leads to a tremendously higher need for bandwidth in the transmission lines that drive the display. Unfortunately the demand outpaces the speed at which newer transmission lines increase their available bandwidth. In this context, image and video compression plays an important role by decreasing the required bandwidth [1]. In order to ensure that the compression algorithms do not degrade the visual quality of the displayed image, compression engineers use image quality metrics.

However, most image quality metrics assume that the image is viewed by the fovea, where the human visual system presents its highest acuity. This motivates the need for image quality metrics that take into account a high field of view. Such image quality metrics can be a valuable tool to design display technologies for future Virtual Reality headsets.

References

[1] F. G. Walls and A. S. MacInnis, "VESA Display Stream Compression for Television and Cinema Applications," IEEE Journal on Emerging and Selected Topics in Circuits and Systems, vol. 6, no. 4, pp. 460-470, December 2016. https://doi.org/10.1109/JETCAS.2016.2602009