The signal calculation unit calculates first, second, and third signal about an amount of blur or high frequency signal, which are related to an edge, based on a first luminance signal, a second luminance signal, and a third luminance signal, respectively. The data expansion unit expands the signals about an amount of blur or high frequency signal respectively to first, second, and third expanded signal data. A control method determination unit sets a back focus area based on a magnitude relation between the first expanded signal data and the second expanded signal data and set a front focus area based on magnitude relation between the first expanded signal data and the third expanded signal data to thereby control focus.