1. An imaging apparatus which shoots a shooting target, comprising: an imaging unit which shoots the shooting target; and an image processing unit which performs image processing on an image of the shooting target, acquired by shooting done by the imaging unit, in such a way as to correct distortion of the image of the shooting target, and which includes a shape acquisition unit which acquires a contour of the image of the shooting target from that image and acquires a shape of the image from the acquired contour, a projection parameter acquisition unit which acquires projection parameters indicating a relationship between the image of the shooting target and a real shooting target from vertex positions of the image of the shooting target by associating the shape of the image acquired by the shape acquisition unit with a shape of the real shooting target, and an image transformation unit which performs image transformation of the image of the shooting target by using the projection parameters acquired by the projection parameter acquisition unit.