1. A method for generating data in a mobile device, the method comprising: projecting an image, stored in the mobile device, to an external screen; capturing an image of the external screen on which the projected image is being displayed and creating a captured image; comparing the projected image with the captured image and extracting an added image from the captured image; and creating data from the extracted image, wherein the projected image comprises a number of areas to which coordinate values are assigned to, respectively, and wherein the extracting of the added image comprises: determining whether the captured image contains the added image; extracting, when the captured image contains the added image, the added image; detecting a coordinate value of a location where the extracted image is located in the projected image; and detecting an area corresponding to the detected coordinate value in the projected image.