Selective Light Field Refocusing for Camera Arrays Using Bokeh Rendering and Superresolution

Camera arrays provide spatial and angular information within a single snapshot. With refocusing methods, focal planes can be altered after exposure. In this letter, we propose a light field refocusing method to improve the imaging quality of camera arrays. In our method, the disparity is first estimated. Then, the unfocused region (bokeh) is rendered by using a depth-based anisotropic filter. Finally, the refocused image is produced by a reconstruction-based superresolution approach where the bokeh image is used as a regularization term. Our method can selectively refocus images with focused region being superresolved and bokeh being esthetically rendered. Our method also enables postadjustment of depth of field. We conduct experiments on both public and self-developed datasets. Our method achieves superior visual performance with acceptable computational cost as compared to the other state-of-the-art methods.

I. Introduction

Athough miniature cameras (e.g., smartphone cameras) have become increasingly popular in recent years, professional photographers still prefer traditional digital single lens reflex (DSLR) to generate esthetical photographs. Due to the large-size image sensors and large-aperture lens, images produced by DSLRs are high in resolution, high in signal-to-noise ratio (SNR), and can be shallow in depth of field (DoF). That is, only a limited range of depths are in focus, leaving objects in other depths suffering from varying degrees of blurs (termed as bokeh). Using bokeh effect properly can blur out non-essential elements in foreground or background, and guide the visual attention of audiences to major objects in a photograph.