A signal from a sensor and an image signal are received, and a position of a signal source is estimated based on the signal from the sensor. Information on a situation expression is extracted based on the signal from the sensor. The situation expression expresses a situation outside a capture range related to the image signal. A display position of the situation expression on a captured image by the image signal is determined using a positional relation between the position of the signal source and the capture range. A size of the situation expression on the captured image is determined depending on a distance between a position of the signal source and a capturing position where the image signal is captured. The situation expression with the determined size is superimposed onto the captured image in accordance with the display position; the captured image superimposed with the situation expression is output.