A zooming system includes a selecting unit, a detection unit, a calculating unit, a controlling unit, and a zooming unit. The selecting unit is configured for selecting a zoom mode based on the presence of faces in a pre-image. The detection unit is configured for detecting facial areas in the pre-image. The calculating unit is configured for calculating a zoom ratio on the basis of a dimensional ratio of the detected facial areas to the pre-image. The zooming unit is controlled by the controlling unit to zoom the imaging device according to the zoom ratio.