1. A specified image position estimating apparatus comprising: a position detection point detecting unit, in a state where three or more position detection marks, each of which is formed such that two or more straight lines intersect with each other or come into contact with each other at one position detection point, are affixed to an original image, detecting said position detection point of each of said position detection marks on said original image; and a specified image position estimating unit estimating a position of a specified image in said original image on the basis of said position detection point detected by said position detection point detecting unit, wherein said position detection point detecting unit includes: a cross correlation calculating unit scanning said original image through the use of a template having the same shape as that of a portion including said position detection point of said position detection mark to calculate a cross correlation between said template and a unit scan area on said original image, and a position detection point specifying unit specifying a position of said position detection point on said original image on the basis of said cross correlation calculated by said cross correlation calculating unit.