A portable terminal including an input unit (1001), through which images are entered, an encoding unit (1002) operable to encode the input images, thereby providing encoded data, a transmitting unit (1003) operable to transmit the encoded data to a communication counterpart, a receiving unit (1006) operable to receive communication counterpart-related information from the communication counterpart, and a mode-determining unit operable to determine an encoding method. The mode-determining unit receives the information on each of the self-terminal and the communication counterpart, thereby providing the determined encoding method. As a result, even when each of the self-terminal and the communication counterpart retains a sufficient level of remaining battery power, the encoding method is properly changed to suppress unwanted power consumption, whereby communication between the self-terminal and the communication counterpart can be made for a longer period of time.