Adaptive camera and illuminator eyetracker
AssigneeTobii Technology AB
InventorsPeter Blixt, Gunnar Troili, Anders Kingback, John Mikael Elvesjö, Mårten Skogö
Life of this patent
Estimating the term…
Abstract
An eye tracker includes at least one illuminator for illuminating an eye, at least two cameras for imaging the eye and a controller. The configuration of the reference illuminator and cameras is such that, at least one camera is coaxial with a reference illuminator and at least one camera is non-coaxial with a reference illuminator. The controller selects one of the cameras to be active to increase an image quality metric and avoid obscuring objects. The eye tracker is operable in a dual-camera mode to improve accuracy.
Claims19
An eye tracker comprising:
- at least one reference illuminator for illuminating an eye;
- a plurality of cameras for imaging the eye, with at least one camera being arranged relative to said at least one reference illuminator such that said at least one camera is able to image a retinal retro-reflection of said at least one reference illuminator, and with at least one other camera being arranged relative to said at least one reference illuminator such that a retinal retro-reflection of said at least one reference illuminator is not visible to said at least one other camera;
- and
- a controller configured to repeatedly evaluate an image quality metric based on at least one image quality factor for images provided by said at least one camera and said at least one other camera, and to select at least one of said at least one camera and said at least one other camera to be active based on the image quality metric.
The eye tracker according to claim:1, wherein said at least one reference illuminator is configured to emit at least one of infrared light and near-infrared light.
A method for selecting a combination of an active illuminator from a plurality of reference illuminators for illuminating an eye and an active camera from a plurality of cameras for imaging the eye, with at least one first combination comprising an illuminator and a camera which are arranged relative to each other such that the camera is able to image a retinal retro-reflection of the illuminator, and with at least one second combination comprising an illuminator and a camera which are arranged relative to each other such that a retinal retro-reflection of the illuminator is not visible to the camera, the method comprising:
- a) defining an image quality metric based on at least one image quality factor;
- b) selecting an imaging mode based on values of the image quality metric for at least two eye images, with one of the eye images being obtained using the first combination and with the other eye image being obtained using the second combination;
- c) selecting an active camera based on values of the image quality metric for eye images acquired using combinations according to the selected imaging mode;
- and
- d) selecting an active reference illuminator based on the centricity of a corneo-scleral reflection of each reference illuminator from the plurality of reference illuminators.
A non-transitory computer-readable medium having computer executable instructions for causing an eye tracker to perform steps comprising:
- selecting a combination of an active illuminator from a plurality of reference illuminators for illuminating an eye and an active camera from a plurality of cameras for imaging the eye, with at least one first combination comprising an illuminator and a camera which are arranged relative to each other such that the camera is able to image a retinal retro-reflection of the illuminator, and with at least one second combination comprising an illuminator and a camera which are arranged relative to each other such that a retinal retro-reflection of the illuminator is not visible to the camera, the selecting comprising
- a) defining an image quality metric based on at least one image quality factor;
- b) selecting an imaging mode based on values of the image quality metric for at least two eye images, with one of the eye images being obtained using the first combination and with the other eye image being obtained using the second combination;
- c) selecting an active camera based on values of the image quality metric for eye images acquired using combinations according to the selected imaging mode;
- and
- d) selecting an active reference illuminator based on the centricity of a cornea-scleral reflection of each reference illuminator from the plurality of reference illuminators.
Dependencies are inferred from the claim text.