Specular highlight removal and depth estimation based on polarization characteristics of light field

Abstract

In this paper, a method based on polarization characteristics of the light field is proposed to remove specular highlight and accurately estimate the depth information for highly reflective surfaces. This method innovatively combines the polarization characteristics and the advantages of the light field imaging to effectively suppress the specular highlight and realize the visual imaging as well as depth estimation. Firstly, a focused light field camera which spatial and angular resolutions can be flexibly adjusted as needed is designed and used to capture the light field images of the target scenes, and the image correction algorithm is performed on the target images to correct image distortion. Then, the relationship between the image grayscale and the polarization angle is established to remove the specular highlight according to the Stokes parameters of light field, and the color transfer algorithm is also used to restore output images. Finally, a method based on entropy mean gradient ratio is designed to quantitatively evaluate the effectiveness of our method. In addition, a depth estimation system of focused light field is built independently to reconstruct the depth information for different highly reflective surfaces by using the proposed method. The experimental results show that our proposed method is suitable for local specular highlight removal under diffuse light source, which provides a new imaging method for highly reflective surfaces.