To enhance the operability of an application in use otherwise deteriorated when an image recognition engine is executed on a background.

An input control section 21 monitors an input state of standard input devices 13 such as a keyboard and a mouse. When the input control section 21 detects that no input operation is made for a prescribed time on the basis of a signal IO20 of a clock 12, the input control section 21 gives a signal IO11 to inform of transition to an idle state to a screen saver control section 23. Then the input control section 21 gives a signal IO14 to turn on a power supply circuit 16A to the power supply circuit 16A via the screen saver control section 23 and an operation recognition section 24. Thus, an image input device 16 is in operation to acquire image data. When the input control section 21 detects the input operation of the standard input devices 13, the input control section 21 outputs a signal IO12 to turn off the power supply circuit 16A so as to stop photographing by the image input device 16.