Homography transfer from point matches

• US 7,003,150 B2
• Filed: 11/05/2001
• Issued: 02/21/2006
• Est. Priority Date: 11/05/2001
• Status: Expired due to Fees

• Current Assignee: Uniloc 2017 LLC (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Trajkovic, Miroslav
• Primary Examiner(s): MARIAM, DANIEL G
• Application Number:
  US09/992,922
• Publication Number:
  US 20030086602A1
• Time in Patent Office: 1,569 Days
• Field of Search: 382/277, 382/285, 382/291, 382/294, 382/300, 382/154, 382/284, 382/287, 345/419, 345/422, 345/424, 345/427, 345/420, 348/40, 348/42
• US Class Current: 382/154
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06V 10/147 Details of sensors, e.g. sensor lenses fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19
• CPC Class Codes: G06V 10/757 Matching configurations of points or features

Abstract

An infinity homography for an image pair within an image sequence is transferred to other image pairs within the image sequence utilizing point matches for the subject image pairs. An image set including the image pair for which the infinity homography is known and a third image are selected. Then intermediate parameters for homography transfer for one image pair overlapping the known infinity homography image pair is computed from the known infinity homography and epipoles and fundamental matrices of the overlapping image pairs, to derive the infinity homography for the selected overlapping image pair. The process may then be repeated until infinity homographies for all image pairs of interest within the image sequence have been derived.

Claims

1. A system for transferring a known infinity homography, comprising:

an image processor processing an image sequence, the image sequence comprising two images to which the known infinity homography applies and an additional image, wherein the image processor;

selects an image pair from the image sequence, the selected image pair including one of the two images to which the known infinity homography applies and the additional image determines intermediate transfer parameters for a homography for the selected image pair; and

derives an infinity homography for the selected image pair from the known infinity homography.

2. The system according to claim 1, wherein the image processor determines a scalar multiple for the homography for the selected image pair and a vector multiple of epipoles for the selected image pair.

3. The system according to claim 1, wherein the additional image is sequential within the image sequence to one of the two images to which the known infinity homography applies.

4. The system according to claim 1, wherein the two images to which the known infinity homography applies are consecutive images within the image sequence.

5. The system according to claim 1, wherein the two images to which the known infinity homography applies are consecutive images i,j within the image sequence, the additional image is image k consecutive with images i,j within the image sequence, wherein the image processor solves ${c_{\mathrm{jk}}}_{}$

[eik]x⁢

Hjk+[eik]x⁢

ejk⁢

zjkT=cik⁢

Fik⁢

Hij⁢

⁢

∞

-1,

where H_jk is a homography for images j,k, c_jk is a scalar multiple for the homography H_jk, e_jk are epipoles for images j,k, $z_{\mathrm{jk}}^T$

is a transpose of an unknown vector multiple for the epipoles e_jk, [e_ik]_x is derived from the epipoles e_ik for images i,k, c_ik is a scalar multiple for a homography H_ik for images i,k, F_ik is a fundamental matrix for images i,k, and $H_{\mathrm{ij}<br><br><br><br>\mathrm{\infty <br><br>}}^{-1}$

is an inverse of the known infinity homography.

6. The system according to claim 1, wherein the known infinity homography relates image points for a second image within the image sequence to image points for a first image within the image sequence.

7. A system for processing an image sequence, comprising:

a video system including an input for receiving the image sequence, the image sequence comprising two images to which a known infinity homography applies and an additional image; and

an image processor within the video system processing the image sequence, wherein the image processor;

selects an image pair from the image sequence, the selected image pair including one of the two images to which the known infinity homography applies and the additional image determines intermediate transfer parameters for a homography for the selected image pair; and

derives an infinity homography for the selected image pair from the known infinity homography.

8. The system according to claim 7, wherein the image processor determines a scalar multiple for the homography for the selected image pair and a vector multiple for epipoles for the selected image pair.

9. The system according to claim 7, wherein the additional image is sequential within the image sequence to one of the two images to which the known infinity homography applies.

10. The system according to claim 7, wherein the two images to which the known infinity homography applies are consecutive images within the image sequence.

11. The system according to claim 7, wherein the two images to which the known infinity homography applies are consecutive images i,j within the image sequence, the additional image is image k consecutive with images i,j within the image sequence, wherein the image processor solves ${c_{\mathrm{jk}}}_{}$

[eik]x⁢

Hjk+[eik]x⁢

ejk⁢

zjkT=cik⁢

Fik⁢

Hij⁢

⁢

∞

-1,

where H_jk is a homography for images j,k, c_jk is a scalar multiple for the homography H_jk, e_jk are epipoles for images j,k, $z_{\mathrm{jk}}^T$

is a transpose of an unknown vector multiple for the epipoles e_jk, [e_ik]_x is derived from the epipoles e_ik for images i,k, c_ik is a scalar multiple for a homography H_ik for images i,k, F_ik is a fundamental matrix for images i,k, and $H_{\mathrm{ij}<br><br><br><br>\mathrm{\infty <br><br>}}^{-1}$

is an inverse of the known infinity homography.

12. The system according to claim 7, wherein the known infinity homography relates image points for a second image within the image sequence to image points for a first image within the image sequence.

13. A method for transferring a known infinity homography for two images within an image sequence to other image pairs within the image sequence, comprising the steps of:

selecting an image pair from the image sequence, the selected image pair including one of the two images to which the known infinity homography applies and an additional image within the image sequence determining intermediate transfer parameters for a homography for the selected image pair; and

deriving an infinity homography for the selected image pair from the known infinity homography.

14. The method according to claim 13, wherein the step of determining intermediate transfer parameters for a homography for the selected image pair further comprises:

determining a scalar multiple for the homography for the selected image pair and a vector multiple for epipoles for the selected image pair.

15. The method according to claim 13, wherein the step of selecting an image pair from the image sequence further comprises:

selecting the additional image from images sequential within the image sequence to one of the two images to which the known infinity homography applies.

16. The method according to claim 13, wherein the two images to which the known infinity homography applies are consecutive images within the image sequence.

17. The method according to claim 13, wherein the two images to which the known infinity homography applies are consecutive images i,j within the image sequence, the additional image is image k consecutive with images i,j within the image sequence, and wherein the step of deriving an infinity homography for the selected image pair from the known infinity homography further comprises:

solving ${c_{\mathrm{jk}}<br><br>\left[e_{\mathrm{ik}}\right]}_x<br><br>H_{\mathrm{jk}}+{\left[e_{\mathrm{ik}}\right]}_x<br><br>e_{\mathrm{jk}}<br><br>z_{\mathrm{jk}}^T=c_{\mathrm{ik}}<br><br>F_{\mathrm{ik}}<br><br>H_{\mathrm{ij}<br><br><br><br>\mathrm{\infty <br><br>}}^{-1},$

 

where H_jk is a homography for images j,k, c_jk is a scalar multiple for the homography H_jk, e_jk are epipoles for images j,k, $z_{\mathrm{jk}}^T$

 

is a transpose of an unknown vector multiple for the epipoles e_jk, [e_ik]_z is derived from the epipoles e_ik for images i,k, c_ik is a scalar multiple for a homography H_ik for images i,k, F_ik is a fundamental matrix for images i,k, and $H_{\mathrm{ij\infty <br><br>}}^{-1}$

 

is an inverse of the known infinity homography.