Patent ID: 8107769

Claim:
An image synthesis device comprising: a computer processor having a memory device storing a computer program which when executed by the processor causes the processor to act as: an image acquisition unit which performs image pickup to successively acquire a plurality of frame images; a characteristic amount calculation unit which calculates a characteristic amount for each of plural image areas on one frame image acquired by the image acquisition unit; an image area extraction unit which extracts an image area having a characteristic amount that is calculated by the characteristic amount calculation unit and is larger than or equal to a predetermined value; an image area searching unit which searches an image area from an other frame image acquired by the image acquisition unit before or after the one frame image based on the characteristic amount of that image area extracted by the image area extraction unit; a moving vector calculation unit which calculates a moving vector in the one frame image and the other frame image based on the image area searched by the image area searching unit and the image area extracted by the image area extraction unit; a cutout width setting unit which sets a cutout width that is a distance between a predetermined reference line image and an estimated line in the one frame based on the moving vector calculated by the moving vector calculation unit, the estimated line being a line on the one frame image corresponding to the predetermined reference line in the other frame image; an image cutout unit which cuts out a partial image, which has the cutout width in an opposite direction of the moving vector from the predetermined reference line, from the one frame image, or cuts out a partial image, which has the cutout width in a direction of the moving vector from the predetermined reference line, from the other frame image; and an image synthesis unit which causes the characteristic amount calculation unit, the image area extraction unit, the image area searching unit, the moving vector calculation unit, the cutout width setting unit, and the image cutout unit to process the plurality of frame images successively acquired by the image acquisition unit to acquire a plurality of partial images, and successively combines and synthesis the plurality of acquired partial images in a manner that reference lines correspond to respective estimated lines.