An image processing apparatus is provided, including a user input interface to input biometric information of at least one user, a processor to process image data to be displayed as an image and to provide a preset service to authenticate a personal identification (ID) and the group ID of a user group including users corresponding to personal IDs, and a controller to specify a personal ID corresponding to biometric information of an input through the user input interface, and to select and authenticate the group ID corresponding to specified personal IDs from the storage when multiple personal IDs are specified. The controller derives interest of the multiple users corresponding to the respective specified personal IDs in the image and selects the group ID corresponding to a personal ID of a user determined to have a high interest.