Method and Device for Identifying and Calibrating Panoramic Optical Systems

• US 20080291318A1
• Filed: 06/09/2008
• Published: 11/27/2008
• Est. Priority Date: 12/09/2005
• Status: Abandoned Application

• Current Assignee: ImmerVision Inc. (f/k/a 6115187 Canada Inc.)
• Original Assignee: ImmerVision Inc. (f/k/a 6115187 Canada Inc.)
• Inventors: ARTONNE, Jean-Claude, KONEN, Pierre, THIBAULT, Simon, VILLEGAS, Mathieu
• Application Number:
  US12/135,545
• Publication Number:
  US 20080291318A1
• Time in Patent Office: Days
• US Class Current: 348/340
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 27/32 Fiducial marks and measuring scales within the optical system
• CPC Class Codes: G03B 37/00 Panoramic or wide-screen photography; Photographing extended surfaces, e.g. for surveying; Photographing internal surfaces, e.g. of pipe
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/663 for controlling interchangeable camera parts based on electronic image sensor signals

Abstract

A method for identifying a panoramic optical system enables its intrinsic characteristics to be semi-automatically or automatically determined so as to be able to subsequently apply the digital processes for appropriate corrections of the perspectives and distortions specific to the identified panoramic optical system. The panoramic optical system has a marking device visible from outside through a front lens, allowing identification by an operator, and/or a marking device directly projected on the image plane through the optical system, for automatic identification and calibration.

Claims

1. An optical system comprising:

an image sensor;

a front lens projecting an image of a scene onto the image sensor; and

a marking device introducing into the optical system at least one mark outside of the scene, the at least one mark being visible in the image provided by the image sensor at the same time as the scene.

2. The optical system according to claim 1, wherein the marking device is configured to project at least one mark on the image sensor, outside of a zone for projection of the image of the scene on the image sensor.

3. The optical system according to claim 1, wherein the marking device includes a light source emitting light which is transmitted or reflected by at least one of the marks, in at least one of the visible spectrum and the non-visible spectrum, towards the image sensor

4. The optical system according to claim 1, wherein at least one of the marks is a hologram.

5. The optical system according to claim 1, wherein at least one of the marks provides information on at least one of an operating state, the optical system, and at least one of a processing and a display system associated with the optical system.

6. The optical system according to claim 1, wherein the marking device is configured to introduce at least one mark through a surface of a lens, the surface being unused for the projection of an image on the image sensor, such that the marks appear in the image provided by the image sensor.

7. The optical system according to claim 6, wherein the unused surface by which the mark is introduced is located on a lateral face of a front lens.

8. The optical system according to claim 6, wherein the unused surface by which the mark is introduced is frosted.

9. The optical system according to claim 1, wherein the marking device is configured to introduce at least one mark in the neighborhood of a diaphragm of the optical system, such that the mark appears in the image supplied by the image sensor.

10. The optical system according to claim 1, wherein the marking device is configured to project at least one mark directly on to the image sensor.

11. The optical system according to claim 1, wherein the marking device includes a light source and a mask forming at least one mark, wherein light rays produced by the light source are introduced into the optical system and reach the image sensor.

12. The optical system according to claim 11, wherein the marking device includes a scattering member located between the light source and the mask.

13. The optical system according to claim 11, wherein the marking device includes a light guide to guide light coming from the light source towards the mask.

14. The optical system according to claim 11, wherein the marking device includes a reflecting surface to redirect light coming from the light source towards the mask.

15. The optical system according to claim 1, further comprising:

a diaphragm through which light rays coming from at least one of the marks pass and reach the image sensor.

16. The optical system according to claim 1, wherein the marking device includes an optical item of positive power to direct light rays from at least one of the marks towards the image sensor.

17. The optical system according to claim 16, wherein the optical item of positive power is a positive lens.

18. The optical system according to claim 1, wherein the marking device includes a reflecting surface to direct light rays from at least one of the marks towards the image sensor.

19. The optical system according to claim 1, wherein the marking device includes a diffractive item to direct light rays coming from at least one of the marks towards the image sensor.

20. The optical system according to claim 1, wherein at least one of the marks is projected onto an intermediate image plane.

21. The optical system according to claim 1, further comprising:

a mechanical alignment device to adjust relative positions of at least one of the marking device, the optical system, and the image sensor.

22. The optical system according to claim 21, wherein the alignment device is configured to at least one of adjust a relative position of the optical system with respect to the image sensor in a plane parallel to that of the image sensor, and adjust the angular position of the optical system around an optical axis of the optical system, with respect to the image sensor.

23. The optical system according to claim 1, wherein the marking device introduces into the optical system at least one mark visible from outside of the optical system.

24. The optical system according to claim 1, wherein at least one mark is introduced by the marking device in the optical system through a surface of the front lens, the surface being unused for the projection of the image of the scene on the image sensor, the mark being visible from the outside of the optical system through the front lens.

25. The optical system according to claim 24, wherein the mark visible from outside of the optical system through the front lens is at least partially formed by a light source.

26. The optical system according to claim 25, wherein the light source is configured to emit light through the front lens towards the outside to illuminate at least part of the scene observed through the optical system.

27. A method of identifying an optical system projecting an image of a scene onto an image sensor, the method comprising:

introducing into the optical system at least one mark outside of the scene, the mark being visible in the image supplied by the image sensor at the same time as the scene;

searching for at least one mark in the image supplied by the image sensor;

identifying at least one of the marks found; and

identifying the optical system from the identified mark.

28. The method according to claim 27, wherein the marks are projected on the image sensor, outside of an image projection zone of the scene on the image sensor.

29. The method according to claim 27, wherein at least one of the marks is projected towards the image sensor by transmitting or reflecting light emitted by a light source, in at least one of the visible spectrum and the non-visible spectrum.

30. The method according to claim 27, further comprising:

introducing at least one mark through one surface of a lens the surface being unused for the projection of an image on the image sensor, such that the marks appear in the image supplied by the image sensor.

31. The method according to claim 30, wherein the surface of the lens through which the mark is introduced is located on a lateral face of a front lens.

32. The method according to claim 27, further comprising:

introducing at least one mark in the neighborhood of a diaphragm of the optical system, such that the mark appears on the image supplied by the image sensor.

33. The method according to claim 27, further comprising:

projecting at least one mark directly onto the image sensor.

34. The method according to claim 27, further comprising:

adjusting relative positions of at least one of the optical system, the image sensor, and a marking device introducing marks in the optical system.

35. The method according to claim 27, further comprising:

at least one of adjusting relative positions of the optical system with respect to the image sensor in a plane, and adjusting an angular position of the optical system around the optical axis of the optical system, with respect to the image sensor.

36. The method according to claim 27, wherein at least one of searching and identifying is performed by a digital method.

37. The method according to claim 27, wherein at least one of the marks is a structured arrangement of geometrical shapes which together form a combination encoding an item of identification information.

38. The method according to claim 27, wherein searching for a mark in the image includes at least one of applying a digital thresholding processing to separate certain colors of the image, and identifying image zones having one characteristic specific to at least one mark.

39. The method according to claim 27, wherein searching for a mark in the image includes at least one of applying a digital processing for shape recognition analyzing the intrinsic geometrical characteristics of shapes detected in the image, and comparing the shapes detected with a reference shape.

40. The method according to claim 27, wherein at least one of the marks is associated with characterizing information of optical properties of the optical system.

41. The method according to claim 27, wherein at least one of the marks represents characterizing information of at least one of the properties and the operating state of a panoramic view system comprising the optical system.

42. The method according to claim 27, wherein at least one of the marks represents a characterizing information of at lest one of a range and a family of optical systems.

43. The method according to claim 27, further comprising:

analyzing at least one of a position, a direction, and dimensions of at least one identified mark to determine, by comparison or calculation, at least one of a position and a direction of the projected image of the scene on the image sensor.

44. The method according to claim 27, further comprising:

analyzing at least one of a position, a direction, dimensions of at least one identified mark to determine, by comparison or calculation, an outline of the projected image of the scene on the image sensor.

45. The method according to claim 27, further comprising:

determining an outline of the projected image of the scene on the image sensor by application of at least one iteration of an outline detection algorithm.

46. The method according to claim 27, further comprising:

associating at least one of information collected by the identification of marks, and information on a panoramic vision system comprising the optical system, with at least one of a computer file, temporary variables and permanent variables.

47. The method according to claim 27, further comprising:

at least one of introducing and or selecting data by an operator, from at least one mark.

48. The method according to claim 27, further comprising:

introducing at least one mark in the optical system such that the mark is visible from outside of the optical system.

49. The method according to claim 27, further comprising:

introducing at least one mark through a surface of a front lens, the surface being unused for the projection of the image of the scene on the image sensor, the mark being visible from the outside of the optical system through the front lens.