To provide a function capable of reducing frame dropping in remote live view display and more accurately displaying a focus area on a remote live view screen in a situation where a communication speed lowers in connecting a digital camera and a computer by USB or wireless and acquiring live view images.

In focus mask display control for displaying a focus area on a live view display screen on a computer side in remote photographing performed while a digital camera and the computer are connected, in order to suppress a decrease in the speed of remote live view display associated with contrast evaluation, live view images to be evaluated are decimated and evaluated. According to an increase/decrease of a communication speed depending on a communication band, a difference is obtained from plural live view images that are contrast evaluation targets and are received from the digital camera in order to enhance the detection accuracy of the focus area, and a focus mask is displayed, so that the detection accuracy is improved.