1. An image processing device, comprising: an image pickup device that captures an image via imaging optics; an image processor configured to perform image processing of the image captured by the image pickup device. a focus detector that detects a focusing condition of the imaging optics; and a focus determination unit that determines whether the focusing condition is assumed to be achieved in focus, wherein the image processor begins background detection when the focus determination unit does not determine that the focusing condition is assumed to be achieved in focus, and the image processor begins face detection when the focus determination unit determines that the focusing condition is assumed to be achieved in focus.