Method for measuring the speed of a vehicle
AssigneeTransport Analysis Ltd
InventorsSamuel Bailey, Mark Steadman
Life of this patent
Estimating the term…
Abstract
A method for measuring the speed of a vehicle from a video motion capture by using the time elapsed between a first wheel of the vehicle reaching a reference position in the image and a second wheel of the vehicle reaching the reference position in an image.
Claims19
A method for determining the speed of a vehicle in a video sequence from an imaging device, comprising:
- a. capturing frames from the video sequence;
- b. determining a time elapsed between a first vehicle portion reaching a reference position in one or more first capture frames and a second vehicle portion reaching the reference position in one or more second capture frames;
- c. calculating vehicle speed based on knowledge of the distance between the vehicle portions and the time elapsed;
- and
- d. annotating one or more of the capture frames with an indicator of at least one of the vehicle portions used to determine the time elapsed.
A method for determining the speed of a vehicle in a video sequence from an imaging device, comprising:
- a. capturing frames from the video sequence;
- b. locating a scene feature in the capture frames that the vehicle passes during the capture;
- c. defining a datum position from that feature in different capture frames, such that the datum position in each of those different capture frames corresponds to an approximately stationary position in the real scene;
- d. determining a time elapsed between a first vehicle portion reaching the datum position in one or more first capture frames and a second vehicle portion reaching the datum position in one or more second capture frames;
- and
- e. calculating vehicle speed based on knowledge of the distance between the vehicle portions and the time elapsed.
A method for determining the speed of a vehicle in a video sequence from an imaging device, comprising:
- a. capturing frames from the video sequence;
- b. determining a time elapsed between a first vehicle portion reaching a reference position in one or more first capture frames and a second vehicle portion reaching the reference position in one or more second capture frames;
- c. calculating vehicle speed based on knowledge of the distance between the vehicle portions and the time elapsed;
- and
- d. filtering the capture frames to at least one of reject capture frames where a distance subtended between the vehicle portions is less than an image size threshold and
- to reject or annotate as unreliable capture frames wherein the angle of the vehicle relative to the camera is sufficiently acute to exceed an angle threshold.
An imaging device configured to determine the speed of a vehicle in a video sequence from an imaging device, wherein the imaging device is programmed to:
- a. capture frames from the video sequence;
- b. determine a time elapsed between a first vehicle portion reaching a reference position in one or more first capture frames and a second vehicle portion reaching the reference position in one or more second capture frames;
- c. calculate vehicle speed based on knowledge of the distance between the vehicle portions and the time elapsed;
- and
- d. annotate one or more of the capture frames with an indicator of at least one of the vehicle portions used to determine the time elapsed.
An imaging device configured to determine the speed of a vehicle in a video sequence from an imaging device, wherein the imaging device is programmed to:
- a. capture frames from the video sequence;
- b. determine a time elapsed between a first vehicle portion reaching a reference position in one or more first capture frames and a second vehicle portion reaching the reference position in one or more second capture frames;
- c. calculate vehicle speed based on knowledge of the distance between the vehicle portions and the time elapsed;
- and
- d. filter the capture frames to at least one of reject capture frames where a distance subtended between the vehicle portions is less than an image size threshold and to reject or annotate as unreliable capture frames wherein the angle of the vehicle relative to the camera is sufficiently acute to exceed an angle threshold.
Dependencies are inferred from the claim text.