Position-information specifying method, position-information specifying device, and position-information specifying program

A position-information specifying device comprising:

• a storing unit configured to store an object image photographed by a first photographing means mounted in a movable body having a predetermined distortion characteristic, a predetermined distortion being caused on the object image due to the predetermined distortion characteristic;
• a first scale plate image corresponding to an image obtained when a first scale plate, which has a first scale and is arranged so as to be opposed to a second photographing means having the predetermined distortion characteristic at a first distance, is photographed by the second photographing means;
• and first reference object information with respect to a first reference object having a first predetermined size;
• an overlapping unit configured to overlap the first scale plate image and the object image with each other;
• a specifying unit configured to specify the first reference object, which is appeared on the object image, while referring to the first reference object information;
• a measuring unit configured to measure an image-size of the specified first reference object by using the first scale of the first scale plate image;
• and
• a calculating unit configured to calculate a first target distance between the first photographing means and the first reference object, based on the image-size of the first reference object, the first predetermined size, and the first distance.

A computer readable medium storing on a non-transitory, non-volatile memory instructions executable by a computer, wherein execution of the instructions implements a position-information specifying method comprising storing an object image photographed by a first photographing means mounted in a movable body having a predetermined distortion characteristic, a predetermined distortion being caused on the object image due to the predetermined distortion characteristic;

• a first scale plate image corresponding to an image obtained when a first scale plate, which has a first scale and is arranged so as to be opposed to a second photographing means having the predetermined distortion characteristic at a first distance, is photographed by the second photographing means;
• and first reference object information with respect to a first reference object having a first predetermined size;
• a step for overlapping the first scale plate image and the object image with each other;
• a step for specifying the first reference object, which is appeared on the object image, while referring to the first reference object information;
• a step for measuring an image-size of the specified first reference object by using the first scale of the first scale plate image;
• and
• a step for calculating a first target distance between the first photographing means and the first reference object, based on the image-size of the first reference object, the first predetermined size, and the first distance.