Foveation scalable video coding with automatic fixation selection

Abstract

Abstract-Image and video coding is an optimization problem. A successful image and video coding algorithm delivers a good tradeoff between visual quality and other coding performance measures, such as compression, complexity, scalability, robustness, and security. In this paper, we follow two recent trends in image and video coding research. One is to incorporate human visual system (HVS) models to improve the current state-of-the-art of image and video coding algorithms by better exploiting the properties of the intended receiver. The other is to design rate scalable image and video codecs, which allow the extraction of coded visual information at continuously varying bit rates from a single compressed bitstream.Specifically, we propose a foveation scalable video coding (FSVC) algorithm which supplies good quality-compression performance as well as effective rate scalability. The key idea is to organize the encoded bitstream to provide the best decoded video at an arbitrary bit rate in terms of foveated visual quality measurement. A foveation-based HVS model plays an important role in the algorithm. The algorithm is adaptable to different applications, such as knowledge-based video coding and video communications over time-varying, multi-user and interactive networks.

Minimizing eyestrain on a liquid crystal display considering gaze direction and visual field of view

“…The algorithm for calculating sensitivity, which has been employed to improve image and video coding efficiency, is called foveation. [14][15][16][17] In this research, eyestrain is measured by calculating a user's gaze position and by determining the user's visual information on the basis of foveation. Humans perceive a dramatic decrease in their visual sensitivity in areas away from the point of gaze.…”

“…The foveation is determined using the contrast threshold (CT) formula, which is based on human contrast sensitivity (CS) data measured as a function of spatial frequency and retinal eccentricity. [14][15][16] CTðf; eÞ…”

“…[14][15][16] The optimal fitting parameters are determined on the basis of previous research (α is 0.106, e 2 is 2.3, and Optical Engineering 073104-2 July 2013/Vol. 52 (7) Lee et al: Minimizing eyestrain on a liquid crystal display considering gaze direction.…”

“…Because a user's gaze position is the foveation point, x f ¼ ðx f 1 ; x f 2 Þ, the distance from x to x f is given by the following equation: 14,16 …”

“…14,16 The cut-off frequency f c , which is an unperceivable high-frequency component, can be obtained by setting CT as 1 (the maximum possible contrast) in Eq. (1): 14,16 f c ðeÞ ¼…”