Abstract
Generally there are more than one object that locate at different depth in a scene of a photographic image. Photographers select a depth as the basis of focusing to present the desired scenarios. However, the visual quality of a photo is limited by the type of camera lens and the skills of the photographer. It cannot present the photographer’s feeling and lead to a failure if we cannot focus on the wanted object properly. To solve this problem, this thesis proposes a concept that photographers don’t need to consider the focusing problem when shooting but refocus on it after computer processing. With limited image information, we propose an object-based refocusing framework to refocus on the wanted object. Through a image labeling game algorithm, we correctly identify the object which we want to refocus and make it more prominent in the image by using a spatial filter. Similarly, we simulate the out-of-focus effect by blurring the background. After these processes, we retrieve a correct focused image that can present the desired depth of field and improve the quality of visual communication.