An accurate camera pose is determined by pairing a first camera with a second camera in proximity to one another, and by developing a known spatial relationship between them. An image from the first camera and an image from the second camera are analyzed to determine corresponding features in both images, and a relative homography is calculated from these corresponding features. A relative parameter, such as a focal length or an extrinsic parameter is used to calculate a first camera's parameter based on a second camera's parameter and the relative homography.
FIELD OF THE INVENTION(1) The exemplary embodiments relate to systems and methods for determining the focal length of a first camera based on the focal length of a second camera positioned in proximity to the first camera.BACKGROUND INFORMATION(2) An accurate camera pose is essential information in many systems, for example, in camera systems intended to broadcast sporting events at stadiums. Some elements of a camera pose (e.g., pan, tilt, roll, position) are sometimes known, fixed, or obtainable with inexpensive sensors. Pan means translation; roll means rotation. The current or instantaneous focal length of a zoomable camera is less frequently available, or of insufficient precision for many applications. In cameras that make their current focal length externally available, the resolution and/or absolute accuracy of the data may be too low for the application that requires focal length data. Thus, using a zoomable camera that outputs its focal length has proven to be unreliable and problematic.(3) In some cases, a portion or an entirety of the elements of a first camera pose can be determined by comparing the current view of the first camera with one or more static images or models of a scene, possibly derived from cameras beforehand. In some other cases, a portion or entirety of the elements of a first camera pose can be determined by comparing the current view of the first camera with concurrent images from one or more additional cameras, some of whose parameters are kno
1. A method, comprising: receiving a first image from a first camera; receiving a second image from a second camera, wherein the second camera is positioned with a relative orientation to the first camera; receiving a camera parameter of the second camera; determining a first set of corresponding feature pairs common to the first image and the second image; determining, based on the first set of corresponding feature pairs, a relative homography between the first image and the second image; and calculating a focal length of the first camera based on the relative homography and the camera parameter of the second camera.
9. An integrated circuit, comprising: circuitry configured to determine a first set of corresponding feature pairs common to a first image and a second image, wherein determining the first set of corresponding feature pairs includes receiving the first image from a first camera and receiving the second image from a second camera, wherein the second camera is positioned with a relative orientation to the first camera; circuitry configured to determine, based on the first set of corresponding feature pairs, a relative homography between the first image and the second image; and circuitry configured to calculate a focal length of the first camera based on the relative homography and a camera parameter of the second camera.
15. A non-transitory computer-readable medium containing instructions that when executed on a computing device results in a performance of the following: receiving a first image from a first camera; receiving a second image from a second camera, wherein the second camera is positioned with a relative orientation to the first camera; receiving a camera parameter of the second camera; determining a first set of corresponding feature pairs common to the first image and the second image; determining, based on the first set of corresponding feature pairs, a relative homography between the first image and the second image; and calculating a focal length of the first camera based on the relative homography and the camera parameter of the second camera.
21. A method, comprising: receiving a first image from a first camera; receiving a second image from a second camera, wherein the second camera is positioned with a relative orientation to the first camera; receiving a camera parameter of the second camera; determining a first set of corresponding feature pairs common to the first image and the second image, wherein the first set of corresponding feature pairs includes corresponding conics and at least one of corresponding points and corresponding lines; determining, by a linear homography calculating module, a relative homography between the first image and the second image based on the first set of corresponding feature pairs; and calculating a camera parameter of the first camera based on the relative homography and the camera parameter of the second camera.