Viewport Perception Based Blind Stereoscopic Omnidirectional Image Quality Assessment

Compared with traditional 2D images, stereoscopic omnidirectional images (SOIs) usually have more complex perceptual factors due to the particularities of imaging and display, making the objective quality assessment of SOIs challenging. In this paper, we construct a large and diverse subjective SOIs database named as NBU-SOID for further research demand. And then, we propose a viewport perception based blind SOIs quality assessment (VP-BSOIQA) method by considering the impacts of viewport, user behavior and stereoscopic perception on human visual system, which is mainly composed of binocular perception model (BPM) and omnidirectional perception model (OPM). In the BPM, a binocular combination perception map is generated by the dimension reduction of stereopair and the weighting of binocular energy to reflect the binocular masking effect. In the OPM, several viewports are first created to ensure the consistency of evaluation objects. Then, the intra-viewport and inter-viewport weighting factors are designed with the common influences of visual attention and peripheral vision sensitivity to aggregate the novel multi-orientation structural features extracted from all potential viewports. Experimental results on the NBU-SOID and SOLID databases demonstrate that BPM and OPM can be robustly combined with the existing 2D image quality assessment (IQA) methods, thus averagely achieving 10.2% and 12.2% performance gain in terms of SRCC, respectively. In addition, the proposed VP-BSOIQA method outperforms the state-of-the-art blind IQA methods in predicting the quality of SOIs.