Process and device for coordinating several images of the same object

• US 5,276,613 A
• Filed: 02/25/1993
• Issued: 01/04/1994
• Est. Priority Date: 12/14/1988
• Status: Expired due to Fees

• Current Assignee: Etienne Schlumberger
• Original Assignee: Etienne Schlumberger
• Inventors: Schlumberger, Etienne
• Primary Examiner(s): Hayes, Gail O.
• Application Number:
  US08/023,179
• Time in Patent Office: 313 Days
• Field of Search: 364/413.16, 364/413.17, 359/117, 356/12-14, 382/2, 382/6, 358/88
• US Class Current: 378/4
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/33 using feature-based methods
• CPC Class Codes: G06T 7/55 from multiple images

Abstract

The process provides for coordinating several images of the same object obtained by transparency projection or photographic like reproduction on one or more image planes from at least two sources, by spatially positioning each image, the exact position of the rays contributing to form the image. A set of at least five points, called "markers", four located in a same plane, and one outside, can be associated to the object. The traces of these markers on the various images can then be used to define the location of the sources and image planes in relation with the marker system. In a more general approach, a required number of identifiable points of the object, but of unknown position, may be used to fully characterise locations in space.

Claims

1. A process for generating a plurality of spatially coordinated images of a three-dimensional object, the process comprising the steps of:

a) providing a plurality of makers disposed in fixed locations relative to the object, the plurality of markers including a first set of at least four markers located in a first reference plane and at least one additional marker spaced from the first reference plane;

b) providing at least two spaced apart imaging radiators for generating substantially point sources of imaging radiation;

c) generating a plurality of images of the object on at least a first image plane from the at least two spaced apart imaging radiators, the nature and location of the markers being such that traces of the markers are projected by the imaging radiators to appear on said plurality of images and are individually identifiable;

d) determining, from the respective projections from each imaging radiator onto each image of at least four of the first set of markers located in the first reference plane, the respective direction of an intersection of each image plane with the first reference plane;

e) then determining, from the respective projection from each imaging radiator onto each image of the at least one additional marker spaced from the first reference plane, the respective location of each imaging radiator and each image plane relative to the first reference plane; and

f) coordinating, by knowledge of the locations determined in step e), the different straight lines contributing to form each projected image of said object on the at least one image plane to form the plurality of spatially coordinated images of the object.

2. A process according to claim 1 wherein the at least one additional marker spaced from the first reference plane comprises a second set of four coplanar markers located in a second reference plane, whereby each of the first and second sets of markers forms with any of the markers in the other set the plurality of markers of claim 1.

3. A process according to claim 1 wherein the first reference plane is parallel to at least one image plane and wherein said at least one additional marker comprises at least two markers spaced from the reference plane.

4. A process according to claim 1, wherein the plurality of markers comprises a plurality of interrelated subsystems, each subsystem comprising at least five markers, and wherein at least one subsystem of markers is projected to appear on each of said images.

5. A process according to claim 1 wherein the first image plane is substantially coincident with the first reference plane.

6. A process for generating a plurality of spatially coordinated images of a three-dimensional object and for determining an enclosed three-dimensional space containing said object, the process comprising the steps of:

a) providing a plurality of markers disposed in fixed locations relative to the object, the plurality of markers including a set of at least two pairs of markers, each pair having a first marker located in a reference plane and a second marker spaced from the reference plane, wherein a line connecting the first and second markers of one pair is parallel to a line connecting the first and second markers of another pair and the lines define a cylindrical projection direction;

b) providing at least two spaced apart imaging radiators for generating substantially point sources of imaging radiation;

c) generating a plurality of images of the object on an image plane that is substantially coincident with the reference plane from the at least two spaced apart imaging radiators, the nature and location of said markers being such that traces of the markers are projected by the at least two imaging radiators to appear on said plurality of images and are individually identifiable;

d) determining the location of each of the at least two imaging radiators from projections of the second marker point of each pair from the at least two imaging radiators, onto the image plane;

e) determining, from the projections of each second marker point onto the image plane and from the locations of the first markers in the reference plane, the projections of said at least two imaging radiators, parallel to said lines connecting the pairs of first and second markers, onto the image plane and the locations of said at least two imaging radiators in space, relative to the locations of said projections of the second markers;

f) determining tangency points on said object with lines connecting said at least two imaging radiators locations determined in step e) and selected pairs of points lying on the outlines of the respective projected images, from step c), of the object on the image plane;

g) constructing cylindrical projections of the tangency points on said object determined in step f) onto the image plane and determining their spatial dimensions;

h) next determining, from the cylindrical projections of said at least two imaging radiators onto the image plane performed in step e), from the cylindrical projections of the tangency points on said object onto the image plane obtained in step g), and from the projections of said object onto the image plane obtained in step b), a polyhedron in the image plane that delimits the cylindrical projection of the object along said direction of cylindrical projection; and

i) determining, from the locations of said at least two imaging radiators obtained in step d) and from the projections of the object onto the image plane obtained in step c) the enclosed three-dimensional space containing said object.

7. A process for generating a plurality of spatially coordinated images of a three-dimensional object, the process comprising the steps of:

a) providing a plurality of markers disposed in fixed locations relative to the object, the plurality of markers including a first set of at least four markers located in a first reference plane and at least one additional marker spaced from the first reference plane;

b) producing on a plurality of image planes a plurality of images of the object by means of radiation from the object, the nature and locations of said markers being such that the markers are projected by collimation to appear as traces on said plurality of images and are individually identifiable;

c) determining, after collimation, traces of the system of markers on each image produced in step b);

d) then determining from the traces of the markers determined in step c), the directions of collimation and the respective locations of each image plane relative to the reference plane; and

e) then positioning in space the different collimation lines contributing to form each projected image of said object on each image plane relative to the reference plane to form the plurality of spatially coordinated images of the object.

8. A process for generating a plurality of spatially coordinated planar images of a three-dimensional object, the process comprising the steps of:

a) associating with the object a system of at least p points disposed in fixed locations relative to the object;

b) providing n imaging radiators for generating imaging radiation;

c) projecting images of the object onto n image planes from the n imaging radiators, the nature and location of said p points being such that all the points are projected to appear as traces on said n images, and the numbers n and p satisfying the relation 2pn≦

29n+3p-S, where S represents the number of known geometric relations in the system;

d) deriving a set of linear equations from the alignment of the p points, the traces of said points on the n image planes, and the n imaging radiators;

e) then calculating, from a matrix of the set of equations derived in step c), the coordinates of the n imaging radiators, of the p points, and of the n images to form the plurality of spatially coordinated images of the three dimensional object.

9. A device for generating a plurality of coordinated planar images of a three-dimensional object, the device comprising:

at least four markers disposed in fixed locations relative to the object, at least two of the markers lying in one reference plane;

a plurality of spaced apart imaging radiators for generating substantially point sources of imaging radiation;

at least one image plane for producing planar images of the object projected by said plurality of spaced apart imaging radiators, the nature and location of said markers being such that traces of the markers are projected by the plurality of spaced apart imaging radiators to appear on each of said images and are individually identifiable;

means for determining the respective direction of an intersection of each image plane with each reference lane from the projections of the markers on the image plane;

means for determining the respective location of each of the plurality of spaced apart imaging radiators and each image plane relative to said markers from said directions of the intersections and the projections of the markers; and

means for spatially coordinating rays from the the plurality of spaced apart imaging radiators which contribute to form each projected image of said object on each image plane from the respective locations of each image plane, and each of the plurality of spaced apart imaging radiators, relative to the locations of said markers to form the plurality of spatially coordinated images of the object.

10. A device according to claim 9 wherein each marker is a geometric element that significantly affects the transmission of radiation emitted by each of the plurality of spaced apart imaging radiators and wherein the markers include at least four geometric elements lying in one reference plane and at least one geometric element spaced rom the one reference plane.

11. A device according to claim 9 wherein each marker is a geometric element that significantly affects the transmission of radiation emitted by each of the plurality of spaced apart imaging radiators and wherein the markers include at least three geometric elements lying in one reference plane that is substantially parallel to one image plane and at least two geometric elements spaced from the one reference plane.

12. A device according to claim 9 wherein the at least one planar imaging means comprises a substrate that is sensitive to the radiation from the plurality of spaced apart imaging radiators and means for containing said substrate, said containing means having a surface that is substantially coincident with the substrate and that defines the one reference plane;

and the at least four markers comprises at least two elongated posts that are parallel to each other, each post having a first end and a second end, each post being fixed by said first end to said surface of the containing means, and the first and second ends of each post comprising marking elements made of a material which affects the transmission of radiation emitted by the plurality of spaced apart imaging radiators.

13. A device according to claim 12 wherein the at least two elongated posts are parallel to each other.

14. A device according to claim 12 wherein the containing means comprises a substantially flat, rigid cartridge forming at least one slot into which the substrate is inserted.

15. A device according to claim 9 wherein the means for determining the respective directions of intersection of each image plane with each reference plane, the means for determining the respective location of each image plane relative to each marker, and the means for spatially coordinating said rays from the the plurality of spaced apart imaging radiators comprise a computer connected to image analyzing devices and programmed to calculate coordinates of the sources, the markers, and each image plane.

16. A device for generating a plurality of spatially coordinated planar images of a three-dimensional object that emits radiation, the device comprising:

a plurality of radiation emitting markers disposed in fixed locations relative to the object, the markers including at least four markers defining at least one reference plane and a fifth marker spaced from the one reference plane;

imaging means for producing images of the object on at least one image plane by collimation of the radiation from the object, the nature and location of said markers being such that the marker radiation causes individually identifiable traces of the markers to appear after collimation on each of said images;

means for determining the collimation direction and the respective location of each image plane relative to the markers from the traces of said markers on the image plane; and

means for spatially coordinating the collimated rays contributing to form each image of said object on each image plane from the respective locations of each image plane and said collimation directions relative to the locations of said markers to form the plurality of spatially coordinated planar images of the object.

17. A device according to claim 16 wherein the means for determining the collimation direction and the means for coordinating the collimated rays comprise a computer connected to image analyzing devices and programmed to calculate coordinates of the object, the markers, and each image plane.