1. A method of measuring geometry parameters of a geometry object with a reference object whose thickness can not be ignored in an image, comprising: providing a reference object which has two parallel imaginative surface planes substantially; providing 4 imaginative point pairs in which one point of said imaginative point pair exists in one of said two parallel imaginative surface planes and other point of same said imaginative point pair exists in other of said two parallel imaginative surface planes, and any line going through two points of any single said imaginative point pair is parallel with other line going through two points of other single said imaginative point pair substantially; providing 4 points out of said 4 imaginative point pairs in one of said two parallel imaginative surface planes form a known size 4 points shape which is represented with a unit of measurement; obtaining an image of said reference object and a geometry object contacting with one of said two parallel imaginative surface planes substantially from a source in which at least 6 points within said 4 imaginative point pairs are distinguishable by a machine; providing a geometry equation of said geometry object is known and geometry parameters of said geometry equation are unknown; identifying said 6 points on said image; computing rest 2 points of said 4 imaginative point pairs by a processor; using 4 points of said 4 imaginative point pairs in one of said two parallel imaginative surface planes with which said geometry object contacts in said image and said known size 4 points shape to calculate a homography matrix by a processor; identifying enough valid points for said geometry equation of said geometry object in said image; calculating said geometry parameters which is represented with said unit of measurement of said geometry equation of said geometry object from said enough valid points for said geometry equation of said geometry object in said image, said geometry equation of said geometry object and said homography matrix by a processor.