Blind quality assessment of light field image based on view and focus stacks

Abstract

Light field imaging can capture rich information of real scenes, but various distortions will inevitably be introduced in the process of light field image processing. Therefore, it is very important to effectively evaluate the quality of light field images. Due to the lack of commercial light field displays, this paper proposes a blind quality assessment method of light field image based on view and focus stack, based on the visualization technology used in the subjective evaluation of light field images and the human brain's perception process of visual information in the study of visual physiology. First, spatiotemporal Gabor filtering is performed on distorted sub-aperture images (SAIs) to extract the spatial and angular information. On the other hand, the SAIs are refocused to obtain the refocused images with different focusing depths, and then the focus stack is filtered by spatiotemporal Gabor filtering to extract the angular information. In addition, the focus stack is detected to form in-focus area and out-of-focus area, and the features related to spatial structure, depth and semantic information of the refocused images are extracted to evaluate the spatial quality. Finally, support vector regression (SVR) is performed to predict the objective scores by establishing the relationship between the features and subjective scores. Experimental results show that our method can well predict the human eye's perception quality of light field images.