Coding distance topologies for structured light patterns for 3D reconstruction

Patent metadata

Field	Value
Publication number	US-10699429-B2
Application number	US-201816104106-A
Country	US
Kind code	B2
Filing date	Aug 16, 2018
Priority date	Aug 19, 2017
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Methods, systems, and devices for 3D measurement and/or pattern generation are provided in accordance with various embodiments. Some embodiments include a method of pattern projection that may include projecting one or more patterns. Each pattern from the one or more patterns may include an arrangement of three or more symbols that are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a most proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a most distal of the remaining symbols in the arrangement. Some embodiments further include: illuminating an object using the one or more projected patterns; collecting one or more images of the illuminated object; and/or computing one or more 3D locations of the illuminated object based on the one or more projected patterns and the one or more collected images.

First claim

What is claimed is:

1. A system for 3D measurement comprising:
a pattern projector that emits one or more patterns, wherein each pattern from the one or more patterns includes an arrangement of three or more symbols that are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a most proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a most distal of the remaining symbols in the arrangement;
an imager; and
a processor configured to estimate one or more 3D locations on an object based on at least:
illuminating the object using the one or more patterns projected from the pattern projector;
collecting one or more images of the illuminated object using the imager; and
computing the one or more 3D locations on the object based on the one or more projected patterns and the one or more collected images.

2. The system of claim 1 , wherein the three or more symbols include three or more spatial codewords.

3. The system of claim 1 , wherein the three or more symbols are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a more proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a more distal of the remaining symbols in the arrangement.

4. The system of claim 1 , wherein a most proximal symbol pair from the three or more symbols has a larger Hamming distance than a most distal symbol pair from the three or more symbols.

5. The system of claim 1 , wherein the arrangement of three or more symbols is repeated.

6. The system of claim 5 , wherein a width of the arrangement of three or more symbols is wide enough such that no two regions of the object are illuminated by a same symbol pair from the three or more symbols and collected on the one or more images.

7. The system of claim 6 , wherein the pattern projector illuminates the object limited to a specific range of distances.

8. The system of claim 6 , wherein at least the pattern projector, the imager, or the processor is dynamically configured for one or more working ranges.

9. The system of claim 1 , wherein an assessment of the most proximal of the remaining symbols from the arrangement and the most distal of the remaining symbols from the arrangement occurs along a single direction.

10. The system of claim 1 , wherein all symbol pairs from the three or more symbols with a proximity less than a block width have a Hamming distance that exceeds the Hamming distance of symbol pairs from the three or more symbols with a proximity more than the block width.

11. The system of claim 1 , wherein at least the pattern projector, the imager, or the processor is dynamically configured for one or more working ranges such that for each of the one or more working ranges, computing each respective 3D location on the object from the one or more 3D locations utilizes information about a region of the pattern no wider than a block width.

12. A pattern projection device comprising:
one or more pattern generators that emit one or more patterns, wherein each pattern from the one or more patterns includes an arrangement of three or more symbols that are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a most proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a most distal of the remaining symbols in the arrangement.

13. The device of claim 12 , wherein the three or more symbols include three or more spatial codewords.

14. The device of claim 12 , wherein the three or more symbols are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a more proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a more distal of the remaining symbols in the arrangement.

15. The device of claim 12 , wherein a most proximal symbol pair from the three or more symbols has a larger Hamming distance than a most distal symbol pair from the three or more symbols.

16. The device of claim 12 , wherein the arrangement of three or more symbols is repeated.

17. The device of claim 16 , wherein a width of the arrangement of three or more symbols is wide enough such that no two regions of the object are illuminated by a same symbol pair from the three or more symbols.

18. The device of claim 17 , wherein the one or more pattern generators are configured to illuminate an object limited to a specific range of distances.

19. The device of claim 17 , wherein the one or more pattern generators are dynamically configured for one or more working ranges.

20. The device of claim 12 , wherein an assessment of the most proximal of the remaining symbols from the arrangement and the most distal of the remaining symbols from the arrangement occurs along a single direction.

21. The device of claim 12 , wherein all symbol pairs from the three or more symbols with a proximity less than a block width have a Hamming distance that exceeds the Hamming distance of symbol pairs from the three or more symbols with a proximity more than the block width.

22. The device of claim 12 , wherein the one or more pattern generators are dynamically configured for one or more working ranges such that for each of the one or more working ranges, computing a 3D location on an object utilizes information about a region of the pattern no wider than the block width.

23. A method of pattern projection comprising:
projecting one or more patterns, wherein each pattern from the one or more patterns includes an arrangement of three or more symbols that are arranged such that for each symbol in the arrangement, a degree of similarity between said symbol and a most proximal of the remaining symbols in the arrangement is less than a degree of similarity between said symbol and a most distal of the remaining symbols in the arrangement.

24. The method of claim 23 , further comprising:
illuminating an object using the one or more projected patterns;
collecting one or more images of the illuminated object; and
computing one or more 3D locations of the illuminated object based on the one or more projected patterns and the one or more collected images.

25. The method of claim 23 , wherein the three or more symbols include three or more spatial codewords.

26. The method of claim 23 , wherein symbol pairs from the three or more symbols that are more proximal in the respective pattern from the one or more patterns are less similar than symbol pairs from the three or more symbols that are less distal in the respective pattern of the one or more patterns.

27. The method of claim 23 , wherein a most proximal symbol pair from the three or more symbols has a larger Hamming distance than a most distal symbol pair from the three or more symbols.

28. The method of claim 23 , wherein the arrangement of three or more symbols is repeated.

29. The method of claim 28 , wherein a width of the arrangement of three or more symbols is wide enough such that no two regions of the object are illuminated by a same symbol pair from the three or more symbols.

30. The method of claim 24 , wherein the illuminating is configured to illuminate the object limited to a speci

Assignees

• Cognex Corp

Inventors

• Liu Zihan Hans
• Bogan Nathaniel
• Hoelscher Andrew
• Moore Eric
• Braker Benjamin

Classifications

• H04N23/56

  provided with illuminating means · CPC title

• G06T2207/10152

  Varying illumination · CPC title

• G06T7/521 Primary

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title

• G06T2207/10028

  Range image; Depth image; 3D point clouds · CPC title

• G06T7/73

  using feature-based methods · CPC title