1. A method of searching for an image, the method comprising: determining whether a unique identifier exists in metadata of an input image to be searched for; when the unique identifier exists in the metadata, searching for an original image of the input image in a target device by using the unique identifier; when the unique identifier does not exist in the metadata, extracting a characteristic value of the input image; and when the unique identifier does not exist in the metadata, searching for the original image by comparing the extracted characteristic value with one or more characteristic values of one or more images stored in the target device.