Geometric Scene Refocusing

TL;DR

This paper introduces a new method for analyzing and manipulating images with shallow depth-of-field, enabling high-fidelity post-capture refocusing while preserving focus and blur details.

Contribution

It presents a composite focus measure and a novel representation for focal stacks, facilitating geometrically correct and detailed refocusing of images.

Findings

Accurately identifies in-focus, dual-focus, and bokeh pixels.

Provides a high-fidelity refocusing algorithm.

Preserves fine focus and defocus details during refocusing.

Abstract

An image captured with a wide-aperture camera exhibits a finite depth-of-field, with focused and defocused pixels. A compact and robust representation of focus and defocus helps analyze and manipulate such images. In this work, we study the fine characteristics of images with a shallow depth-of-field in the context of focal stacks. We present a composite measure for focus that is a combination of existing measures. We identify in-focus pixels, dual-focus pixels, pixels that exhibit bokeh and spatially-varying blur kernels between focal slices. We use these to build a novel representation that facilitates easy manipulation of focal stacks. We present a comprehensive algorithm for post-capture refocusing in a geometrically correct manner. Our approach can refocus the scene at high fidelity while preserving fine aspects of focus and defocus blur.