Method and arrangement for detecting the spatial form of an object

• US 20030142863A1
• Filed: 01/16/2003
• Published: 07/31/2003
• Est. Priority Date: 07/19/2000
• Status: Active Grant

• Current Assignee: Corpus E AG
• Original Assignee: Corpus E AG
• Inventors: Massen, Robert
• Granted Patent: US 7,209,586 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• CPC Class Codes: A43D 1/025 comprising optical means, e.g. mirrors, photo-electric cells, for measuring or inspecting feet
• CPC Class Codes: A61B 5/1074 Foot measuring devices
• CPC Class Codes: G01C 11/06 by comparison of two or more pictures of the same area
• CPC Class Codes: G01C 15/02 Means for marking measuring points

Abstract

The invention relates to a method of detecting the 3D shape of objects, in which the object is pressed into a plastically deformable mass provided with markers adapted to be evaluated photogrammetrically. After removal of the object from the marked mass, a plurality of photogrammetric images are taken from different views, and the images are evaluated photogrammetrically, the 3D shape of the object being calculated using an association of the markers corresponding in the images. The invention further relates to a corresponding arrangement for carrying out the method and is particularly suited for the detection of the 3D shape of objects whose 3D shape changes under load. One example of this would be the measurement of human feet.

Claims

1. A method of detecting the 3D shape of an object (3), wherein a plastically deformable mass (2) is provided which has at least one surface portion (7) provided with markers (4) adapted to be evaluated photogrammetrically, the object is impressed on the surface portion (7) into the mass (2) such that the mass (2) deforms corresponding to the 3D shape of the object (3), the object (3) is removed from the deformed mass (2), a plurality of images are taken of the deformed mass (2) provided with the markers (4) from respective different views, and the 3D shape of the object (3) is determined from the images by means of a photogrammetric process.

2. The method as claimed in claim 1, wherein in the photogrammetric process an image processing of the images is performed, in which the markers (4) respectively corresponding in the images are associated with one another, and the 3D shape of the object (3) is determined using the marker association.

3. The method as claimed in claim 1 or 2, wherein the provision of the plastically deformable mass which has at least one surface portion provided with markers adapted to be evaluated photogrammetrically is effected by providing a plastically deformable mass having bodies enclosed therein which have a color that is different from the color of the mass and which are visible from outside in the area of the surface portion (7).

4. The method as claimed in claim 1 or 2, wherein the provision of the plastically deformable mass which has at least one surface portion provided with markers adapted to be evaluated photogrammetrically is effected by applying markers of a color that is different from the color of the mass onto the surface portion of the plastically deformable mass.

5. The method as claimed in claim 1 or 2, wherein the provision of the plastically deformable mass which has at least one surface portion provided with markers adapted to be evaluated photogrammetrically is effected by placing an elastic envelope provided with markers on the surface portion of the plastically deformable mass.

6. The method as claimed in any of the preceding claims, wherein the markers consist of point markers and area markers, each of the area markers comprising a plurality of point markers, forming a background of the point markers, and having a characteristic optical configuration.

7. The method as claimed in claim 6, wherein in the image processing of the images first the area markers respectively corresponding in the images are associated with one another using their characteristic optical configurations, and then the point markers comprised by the area markers and respectively corresponding in the images are associated with one another with the aid of the area marker association, and using the point marker association, the 3D shape of the object is determined by means of a photogrammetric evaluation process.

8. The method as claimed in any of the preceding claims, wherein the plastically deformable mass is provided in a mold (1) which serves to hold the mass.

9. The method as claimed in any of the preceding claims, wherein the object (3) is a body part of a person, whose 3D shape is to be measured under load.

10. The method as claimed in claim 9, wherein the object (3) is a foot.

11. The method as claimed in any of claims 1 to 8, wherein the object is a statue.

12. The method as claimed in any of the preceding claims, wherein the plastically deformable mass provided is a reversibly deformable mass which, once the images have been taken, is returned to its original form which it had taken prior to the impression by the object.

13. The method as claimed in claim 12, wherein the reversibly deformable mass is returned to its original form under the influence of energy, heat, light, or mechanical energy.

14. The method as claimed in any of the preceding claims, wherein prior to obtaining the images, a measuring rod is arranged beside the surface portion of the deformable mass bearing the markers adapted to be evaluated photogrammetrically, the measuring rod having arranged thereon at least two markers at a known distance from each other, adapted to be evaluated photogrammetrically.

15. The method as claimed in claim 14, wherein at least two of the images of the mass provided with markers are taken such that the measuring rod is included in the image taken.

16. An arrangement for detecting the 3D shape of an object by photogrammetry, comprising an imaging system (5) for obtaining photogrammetric images and a system for photogrammetrically evaluating the images and for determining the 3D shape of the object, characterized in that the arrangement further comprises a plastically deformable mass (2) which has at least one surface portion (7) provided with markers (4) adapted to be evaluated photogrammetrically.

17. The arrangement as claimed in claim 16, wherein bodies of a color different from the color of the mass are provided to serve as markers, the bodies being enclosed in the mass and being visible from outside.

18. The arrangement as claimed in claim 16, wherein color markings serving as markers are provided on the surface portion of the mass and have a color that is different from the color of the mass.

19. The arrangement as claimed in claim 16, wherein an elastic envelope is provided having markers applied thereon, which is pulled over the mass in the area of the surface portion and adheres to the mass.

20. The arrangement as claimed in any of claims 16 to 19, wherein further provided is a mold (1) to hold the mass.

21. The arrangement as claimed in any of claims 16 to 20, wherein the plastically deformable mass is a reversibly deformable mass.

22. The arrangement as claimed in claim 21, wherein the reversibly deformable mass is made such that it can be returned to its original form under the influence of energy, heat, light, or mechanical energy.

23. The arrangement as claimed in any of claims 16 to 22, wherein a measuring rod is provided which bears at least two markers adapted to be evaluated photogrammetrically, arranged at a known distance from each other, the measuring rod being arranged beside the surface portion of the deformable mass.

24. The arrangement as claimed in claim 20 and 23, wherein the measuring rod is connected to the mold holding the mass.