US 10,757,333 B2 · Method for determining bias in an inertial measurement unit of an image acquisition device

Abstract

A method for determining bias in an inertial measurement unit of an image acquisition device comprises mapping at least one reference point within an image frame into a 3D spherical space based on a lens projection model for the image acquisition device to provide a respective anchor point in 3D space for each reference point. For reference points within a given image frame, an estimate of frame-to-frame motion at the reference point between the given frame and a previously acquired frame is obtained; a measure of device orientation for an acquisition time of the reference point in the given frame and the previously acquired frame, the measure including a bias component, is obtained from the inertial measurement unit; a corresponding anchor point is projected in 3D space according to a difference in the measure of device orientation in the given frame and the previously acquired frame to provide a 3D vector Vm; a result of the estimated frame-to-frame motion for the point from the given frame is projected into the previously acquired frame into 3D space to provide a 3D vector Ve; and a cross product Vc of the 3D vectors Vm and Ve is used to update a bias component value.

Claims20

Dependent claims

A method comprising:

determining a motion between a first point depicted in a first image frame and a second point depicted in a second image frame;
determining, using an inertial measurement unit, a first orientation of a device at a first time, the first time corresponding to the first image frame;
determining, using the inertial measurement unit, a second orientation of the device at a second time, the second time corresponding to the second image frame;
mapping a first vector in a three-dimensional space using at least the motion;
mapping a second vector in the three-dimensional space using at least the first orientation and the second orientation;
and
determining, based at least in part on the first vector and the second vector, a value indicating a bias of an output of the inertial measurement unit.

4 more elements

A method comprising:

determining a motion between a first point depicted in a first image frame and a second point depicted in a second image frame;
determining, using an inertial measurement unit, a first orientation of a device at a first time, the first time corresponding to the first image frame;
determining, using the inertial measurement unit, a second orientation of the device at a second time, the second time corresponding to the second image frame;
determining a difference between the first orientation and the second orientation;
and
determining, based at least in part on the motion and the difference, a value indicating a bias of an output of the inertial measurement unit, wherein determining the value indicating the bias of the output of the inertial measurement unit comprises:
generating a first vector based at least in part on the motion;
generating a second vector based at least in part on the difference;
and
determining, based at least in part on the first vector and the second vector, the value indicating the bias of the output of the inertial measurement unit.

7 more elements

A device comprising:

an image capture device;
an inertial measurement unit;
at least one processor;
and
memory storing instructions that, when executed by the at least one processor, cause the device to perform operations comprising:
determining a motion between a first point depicted associated with a first image frame and a second point associated with a second image frame;
determining, using the inertial measurement unit, a first orientation of the device at a first time, the first time corresponding to the first image frame;
determining, using the inertial measurement unit, a second orientation of the device at a second time, the second time corresponding to the second image frame;
mapping a first vector in a three-dimensional space using at least the motion;
mapping a second vector in the three-dimensional space using at least the first orientation and the second orientation;
and
determining, based at least in part on the first vector and the second vector, a value indicating a bias of an output of the inertial measurement unit.

9 more elements

Dependencies are inferred from the claim text.

Method for determining bias in an inertial measurement unit of an image acquisition device

Life of this patent

Method for determining bias in an inertial measurement unit of an image acquisition device

Life of this patent

Abstract

Claims20