COMPARATOR DEVICE USING PARALLAX OF TWO PHOTOGRAPHS

• US 3,578,863 A
• Filed: 07/12/1967
• Issued: 05/18/1971
• Est. Priority Date: 07/15/1966
• Status: Expired due to Term

• Current Assignee: Farrand Richard George
• Original Assignee: Farrand Richard George
• Inventors: FARRAND RICHARD GEORGE
• Application Number:
  US04/652,589
• Time in Patent Office: 1,406 Days
• US Class Current: 356/2
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 11/06 by comparison of two or more pictures of the same area

Abstract

This invention aims at providing a simple means for finding a location in space and for determining the three dimensional coordinates of any object which is shown on a photograph or a pair of photographs. To do this I superimpose one photograph of the object over another photograph of the same object which shows a parallax difference with respect to the first photograph and I then compare the differences in the separations of the vertical centerlines of the photographs with one of the photographs displaced horizontally relatively to the other to superimpose successively a series of pairs of images of the identical points. I also provide an apparatus for making the comparison including a viewing box with a screen and some means of fixing the photograph in relation to the screen and a carriage to move another photograph horizontally across the screen relatively to the first photograph.

Claims

1. A method of determining the three dimensional coordinates of an object depicted in first and second positive photographs, the second positive photograph exhibiting parallax relative to the first positive photograph, which comprises:

defining a vertical centerline in each of said first and second positive photographs, the centerline in the first positive photograph having the same relative position and orientation as the centerline in the second positive photograph relative to the object depicted in said photographs;

superimposing said first positive photograph of the object over said second positive photograph of the same object;

aligning the centerlines of said photographs to obtain a reference position;

displacing one of said photographs laterally in a direction perpendicular to the centerlines and relative to the other photograph to superimpose successively a series of pairs of images of identical points; and

measuring the differences in the separations of the vertical centerlines of said photographs at a point of coincidence of each of said pAirs of images, said differences in the separations having a functional relationship to the actual three dimensional coordinates of the object, and converting the resultant measurements of the differences in the separations into actual coordinates of said object.

2. A method of obtaining a measurement which is related to the depth of an object depicted in first and second positive photographs, the second positive photograph exhibiting parallax relative to the first positive photograph, which comprises:

defining a vertical centerline in each of said first and second positive photographs, the centerline in the first positive photograph having the same relative position and orientation as the centerline in the second positive photograph relative to the object depicted in said photographs;

superimposing said first positive photograph of the object over said second positive photograph of the same object;

aligning the centerlines of said photographs to obtain a reference position;

displacing one of said photographs laterally in a direction perpendicular to the centerlines and relative to the other photograph to superimpose images of identical points which appear in said photographs; and

measuring the distance between the vertical centerlines of said photographs when said images of identical points are superimposed to obtain a measurement related to the depth of the object.