Depth from Spectral Defocus Blur

Abstract

This paper proposes a method for depth estimation from a single multispectral image by using a lens property known as a chromatic aberration. The chromatic aberration cause that the light passing through the lens is refracted depending on the wavelength. The refraction cause that rays vary their angle depending on the wavelength and generate a change in focal length which leads to a defocus blur for different wavelengths.We show that the chromatic aberration provides clues to recover depth maps from a single multispectral image if we assume that the defocus blur is Gaussian. The proposed method needs only a standard wide-aperture lens which naturally exhibits the chromatic aberration and a multispectral camera. Moreover, we use a simple yet effective depth of field synthesis method to calculate the derivatives and obtain all-in-focus images necessary to approximate spectral derivatives. We verified the effectiveness of the proposed method on various real-world scenes.