1. An image processing method, the method comprising: capturing a first image, a second image, and a third image, which are captured with a different focus for a same subject and background; setting a subject portion and a background portion using the first and second images; combining the subject portion of the first image and the background portion of the third image with each other to obtain an narrow depth-of-field (DOF) image; and performing image processing on the obtained narrow DOF image.