An image generator is provided which obtains a specular image and a diffuse image from an image acquired by a polarized light field camera by separating two reflection components of a subject, and a control method thereof. The image generator may include a main lens, a polarizing filter part, a photosensor, a microlens array, and a controller that generates a single image in response to the electrical image signal and extracts, from the generated image, a specular image and a diffuse image that exhibit different reflection characteristics of the subject.