1. An image correction method for correcting a first image in a projector for displaying the first image in a projection area, the method comprising the steps of: (a) projecting a second image corresponding to a size of an image formation panel of the projector in the projection area; (b) capturing a third image including the projected second image and a frame defining the projection area; (c) adjusting a zoom lens of the projector so that the projected second image encompasses the frame in the third image; and (d) executing keystone correcting of the first image in the projector so that the corrected first image is displayed within the frame.