PVBLiF: A Pseudo Video-Based Blind Quality Assessment Metric for Light Field Image
Zhengyu Zhang, Shishun Tian, Wenbin Zou, Luce Morin, Lu Zhang
Abstract
Going beyond traditional 2D imaging is not only an emerging trend of imaging technology, but also the key to a more immersive user experience. Light Field Image (LFI) is a typical high-dimensional imaging format, and the quality evaluation of which is very challenging but necessary. In this article, we propose a novel Pseudo Video-based Blind quality assessment metric for Light Field image (PVBLiF). In contrast to most previous Light Field Image Quality Assessment (LF-IQA) metrics, in which different types of 2D representations derived from LFI are used for quality assessment indirectly, our metric exploits a more intuitive 3D representation, named Pseudo Video Block Sequence (PVBS), to evaluate the perceptual quality of LFI. For this purpose, we first divide the LFI into a massive number of non-overlapping PVBSs, which simultaneously contain spatial and angular information of LFI. Then, we propose a novel network (named PVBSNet) based on Convolutional Neural Networks (CNNs) to extract the spatio-angular features of PVBS and further evaluate the PVBS quality. The proposed PVBSNet consists of four stages: multi-information division, intra-feature extraction, cross-feature fusion, and quality regression. Finally, a Saliency- and Variance-guided Pooling (SVPooling) method is presented to integrate all the PVBS quality into the overall quality of LFI. The proposed PVBLiF metric has been extensively evaluated on three widely-used LFI datasets: Win5-LID, NBU-LF1.0, and SHU. Experimental results demonstrate that our proposed PVBLiF metric outperforms state-of-the-art metrics and is capable of highly approximating the performance of human observers.