Visibility threshold of compressed stereoscopic image: effects of asymmetrical coding

Abstract

Existing perceptual researches on stereoscopic image mainly focus on proving the effectiveness of binocular suppression theory in reducing bandwidth during asymmetrical coding. However, they care little about the threshold below which the phenomena exist. To determine the threshold as visible in the asymmetrical stereoscopic image coding, the relationship between visibility threshold and coding parameter or objective quality under practical viewing conditions is investigated in this paper. Perceptual experiments are designed by using the paired comparison methods. Experimental results show that the visible threshold is dependent on stereoscopic image content, coding parameter and objective quality of the left (dominant) view in asymmetrical stereoscopic image coding. Furthermore, we model the visible threshold as a linear function of the quantisation parameter of the left (dominant) view for asymmetrical coding. Then based on the model, we build a looking-up table for practical coding. The concise linear model can serve as an upper bound for controlling perceived quality of asymmetrical coding.