1. An image processing apparatus, comprising: a light field data position determiner configured to determine a position of a portion of light field data among light field data corresponding to a scene, according to a desired focusing position; a refocusing image generator configured to generate a refocusing first image by use of the position determined portion of light field data; a high resolution image generator configured to generate a high-resolution image comprising a predetermined setting ratio, relative to the refocusing first image; a synthesis ratio determiner configured to determine a ratio for local synthesis between the high-resolution image and an enlarged image of the refocusing first image, by use of a similarity with respect to the position determined portion of light field data; and an image synthesizer configured to generate a synthesized image by synthesizing the high-resolution image and the enlarged image of the refocusing first image, according to the local synthesis ratio.