Method and device for obtaining a digital panoramic image of constant color

• US 20040109078A1
• Filed: 08/15/2003
• Published: 06/10/2004
• Est. Priority Date: 02/16/2001
• Status: Abandoned Application

• Current Assignee: ImmerVision Inc. (f/k/a 6115187 Canada Inc.)
• Original Assignee: Immervision International Pte. Ltd.
• Inventors: Bonavita, Herve, Roulet, Patrice, Villegas, Mathieu, Artonne, Jean-Claude, Blanc, Benjamin
• Application Number:
  US10/641,931
• Publication Number:
  US 20040109078A1
• Time in Patent Office: Days
• US Class Current: 348/335
• CPC Class Codes: G03B 27/735 in dependence upon automatic analysis of the original
• CPC Class Codes: H04N 1/6033 using test pattern analysis H04N1/6055 takes precedence

Abstract

A method for correcting the color of a digital panoramic image obtained uses at least one initial wide-angle image the image points of which are transferred into a three-dimensional coordinate system. The method includes inserting a color-grading zone into the initial image at the time of the exposure, the grading zone comprising at least three primary colors combined or presented in the form of a sequence of colors; detecting the color-grading zone in the panoramic image, performed by means of a digital image analysis algorithm; and correcting the colors of the image points of the digital panoramic image, performed with reference to the primary colors present in the grading zone.

Claims

1. A camera support device, comprising a color-grading component arranged so that the color-grading component appears in an exposure when a camera fitted with a panoramic lens is attached to the support device.

2. The support device according to claim 1, wherein the color-grading component comprises at least three primary colors combined or presented in the form of a sequence of colors.

3. The support device according to claim 2, wherein the color-grading component comprises a repetition of a sequence of three primary colors.

4. The support device according to claim 3, wherein the color-grading component comprises, between two sequences of three primary colors, a separation zone comprising at least one color chosen out of the following colors:

black, white and grey.

5. The support device according to claim 1, wherein the color-grading component is circular and concentric to the axis of rotation of the support device.

6. The support device according to claim 1, further comprising a compass and means for attaching the compass arranged so that the compass appears in an exposure when a camera fitted with a panoramic lens is attached to the support device.

7. The support device according to claim 6, wherein the color-grading component is circular and concentric to the face of the compass.

8. The support device according to claim 7, wherein the color-grading component is arranged on the periphery of the face of the compass.

9. The support device according to claim 7, wherein the compass comprises a face having an artificial color designed to be distinguished from the natural colors of an exposure during a computer image analysis aiming to find the location of the face of the compass.

10. The support device according to claim 1, further comprising a tongue for locating an arbitrary orientation, the position of which can be set manually so that the tongue appears in an exposure when a camera fitted with a panoramic lens is attached to the support device.

11. The support device according to claim 10, wherein the tongue extends over the face of a compass.

12. The support device according to claim 1, comprising means for attaching a camera fitted or capable of being fitted with a first lens, and means for attaching an adapter lens, particularly a panoramic adapter lens, arranged to hold the adapter lens in line with the first lens without the need to attach the adapter lens to the camera.

13. The support device according to claim 12, comprising means for rotating around an axis, the means for attaching the adapter lens being arranged to hold the adapter lens in a position such that the axis of rotation of the support device is located substantially in the nodal plane of the front lens of the adapter lens.

14. A method for correcting the color of a digital panoramic image obtained by transferring the image points of at least one initial image into a three-dimensional coordinate system, the method comprising:

inserting a color-grading zone into the initial image at the time of the exposure, the grading zone comprising at least three primary colors combined or presented in the form of a sequence of colors,

detecting the color-grading zone in the panoramic image, performed by means of a digital image analysis algorithm, and

correcting the colors of the image points of the digital panoramic image, performed with reference to the primary colors present in the grading zone.

15. The method according to claim 14, wherein the insertion of a color-grading zone into the initial image comprises arranging a color-grading component in the shooting field of a panoramic lens, so that the color-grading component appears on the initial image.

16. The method according to claim 14, wherein the color correcting step comprises:

determining the gamma of the primary colors of the color-grading zone, performed with reference to a reference color intensity allocated to each primary color, and

a gamma correcting step applied to all or part of the image points of the digital panoramic image, performed by means of the gamma (γ

r, γ

g, γ

b) of the primary colors of the color-grading zone.

17. The method according to claim 16, wherein the step of determining the gamma comprises a calculation of the mean value (r, g, b) of the intensity of the primary colors present in the grading zone.

18. The method according to claim 16, wherein:

determining the gamma and the gamma correcting step are applied to sectors of the panoramic image and are repeated for each following sector until the entire panoramic image is covered,

the gamma is determined for each sector by means of the primary colors of the grading zone that are present in the sector considered, and

the gamma correction applied to the image points of the sector considered is performed by means of the gamma of the primary colors of the grading zone present in the sector considered.

19. The method according to claim 16, wherein the color-grading zone comprises at least one sequence of three primary colors.

20. The method according to claim 16, wherein:

the image points are transferred into a spherical coordinate system,

the color-grading zone fills a sphere sector in the spherical panoramic image, and

the step of determining the gamma of the primary colors of the color-grading zone comprises angularly scanning the sphere sector comprising the grading zone.

21. The method according to claim 14, wherein the initial image is a photograph.

22. The method according to claim 14, wherein the initial image is delivered by a video camera.