1. A method for processing a light-field image, comprising: acquiring a light-field image; acquiring an occlusion tag function of each unit image in the light-field image, and determining a cost function for offset estimation of each unit image according to intensity change information and gradient change information that are of each unit image in the light-field image and the occlusion tag function of each unit image; acquiring an offset of each unit image in the light-field image by using the cost function; and reconstructing a high-resolution light field by using the offset of each unit image.