In a camera which electronically realizes panning, tilting, and zooming, on the basis of the luminance detected in each frame period (n−1), a condition of exposure for two frame periods thereafter (n+1), and digital gain for three frame periods thereafter (n+2) are set. When an instruction for changing the extracted region is received in a certain frame period (n−1), the region extracted from the image is changed three frame periods thereafter. It is possible to achieve a stable exposure control by which the luminance of the image varies little even when the region extracted from the image is switched.