An image-data receiving unit receives image data from other image communication apparatus. A storing unit stores therein the image data. An output unit outputs the image data stored in the storing unit. A reading unit reads the image data output by the output unit. An extracting unit extracts a difference between the image data read by the reading unit and the image data stored in the storing unit. A determining unit determines whether the difference extracted by the extracting unit satisfies a predetermined condition. A control unit controls a transmission of a message to other image communication apparatus based on a result of determination by the determining unit.