METHOD AND APPARATUS FOR DIGITAL VIDEO LATENCY REDUCTION BY REAL-TIME WARPING

• US 20120249784A1
• Filed: 04/01/2011
• Published: 10/04/2012
• Est. Priority Date: 04/01/2011
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Olson, Andrew C., Brinck, Brian E., Konyn, John N.
• Granted Patent: US 8,917,322 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G06T 3/18 Image warping, e.g. rearranging pixels individually
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

In one aspect, video latency reduction by real-time warping is described. In one aspect, an original geometric image model of a digital video frame is adjusted according to a video frame latency, to form an adjusted geometric image model. A geometric image model may represent a field of view from a remote camera used to capture the digital video frame. The adjusted geometric image model may be overlaid onto the original geometric image model to capture a warped image. In one aspect the warped image is re-projected according to the adjusted geometric image model to form a re-projected image. The re-projected image may then be displayed to approximate a real-time field of view from a camera used to capture the digital video frame. In one aspect, an attitude and runway alignment of an unmanned aerial vehicle may be controlled using a displayed, re-projected image. Other aspects are described and claimed.

Claims

1. A method for digital video latency reduction of a received digital video frame captured by a remote camera, the method comprising:

adjusting an image model of the received digital video frame according to an approximate field of view from the remote camera at a time the digital video frame is received to form an adjusted image model;

overlaying the adjusted image model onto the image model of the received digital video frame to capture a warped image; and

re-projecting the warped image according to the adjusted image model to form a re-projected image that approximates a real-time field of view from the remote camera used to capture the received digital video frame.

2. The method of claim 1, wherein the remote camera is attached to an unmanned aerial vehicle, the method further comprising:

displaying a plurality of re-projected images based a plurality of received digital video frames captured by the remote camera on a display at a remote location; and

controlling an attitude and runway alignment of the unmanned aerial vehicle in response to user commands from viewing the plurality of displayed, re-projected images.

3. The method of claim 1, further comprising:

storing a camera attitude for each recorded digital video frame at a time that each digital video frame is recorded according to received navigation data.

4. The method of claim 3, wherein the camera attitude for each recorded frame is received over a wireless link.

5. The method of claim 1, wherein overlaying further comprises:

mapping the received digital video frame onto the adjusted image model to form the warped video frame; and

reducing a field of view of the warped video frame to eliminate one or more edges of the warped video frame to form the re-projected image.

6. The method of claim 1, wherein adjusting further comprises:

reverse-mapping the received digital video frame to determine an original geometric image model corresponding to a field of view of the remote camera at a digital video frame capture time; and

modifying the image model of the received digital video frame to approximate the real-time field of view from the remote camera at the time the digital video frame is received to form the adjusted image model.

7. The method of claim 1, further comprising:

rendering, using a graphics processing unit, a composite two-dimensional display of the digital video frame by applying the video frame to a three-dimensional geometry corresponding to a field of view of the remote camera at the time the video frame is captured to approximate a real-time view from a vehicle including the camera.

8. A non-transitory computer readable medium having processor-executable software instruction to perform a method digital video latency reduction of a received digital video frame captured by a remote camera, comprising:

re-mapping the digital video frame to determine an original geometric image model corresponding to a field of view from the remote camera used to capture the digital video frame at a digital video frame capture time;

modifying the original geometric image model according to an approximate field of view from the remote camera at a digital video frame receive time to form an adjusted geometric image model;

overlaying the adjusted geometric image model onto the original geometric image model to capture a warped image; and

reducing a field of view of the warped video frame image to eliminate one or more edges of the warped video frame image to form a re-projected image; and

displaying the re-projected image to approximate a real-time field of view from the camera at the video frame receive time.

9. The non-transitory computer readable medium of claim 8, further comprising:

maintaining an attitude and runway alignment of an unmanned aerial vehicle using a displayed, re-projected image.

10. The non-transitory computer readable medium of claim 9, wherein reverse-mapping further comprises:

adjusting an original geometric image model of a digital video frame according to a delay between a video frame receive time a video frame capture time to form the adjusted geometric image model

11. The non-transitory computer readable medium of claim 8, wherein displaying further comprises:

rendering, using a graphics processing unit, a composite two-dimensional display of the video frame by applying the video frame to a three-dimensional geometry corresponding to a field of view of the camera at the video frame capture time.

12. The non-transitory computer readable medium of claim 11, further comprising:

storing a camera attitude for each recorded frame, at a time that each frame is recorded, according to received navigation data, wherein the camera attitude for each recorded frame is received over a wireless link.

13. The non-transitory computer readable medium of claim 8, wherein overlaying further comprises:

mapping the video frame onto the adjusted geometric image model to form the warped video frame image.

14. The non-transitory computer readable medium of claim 8, wherein overlaying further comprises:

warping each frame of digital video to approximate a geometry of a future video frame in real-time.

15. A system for digital video latency reduction of a received digital video frame captured by a remote camera, comprising:

a transceiver configured to receive the digital video frame and a camera geometry at a digital video frame capture time;

a memory operable to store the received digital video frame and the camera geometry;

a graphics processing unit operable to determine an original geometric image model corresponding to a field of view from the remote camera used to capture the digital video frame, at the digital video frame capture time, to overlay an adjusted geometric image model onto the original geometric image model to capture a warped image, the adjusted geometric image model corresponding to an approximate field of view from the remote camera at a digital video frame receive time, and to reduce a field of view of the warped video frame to eliminate one or more edges of the warped image to form a re-projected image;

a display operable to display the re-projected image to approximate a field of view from the camera used to capture the video frame according to a location of the camera at the video frame receive time; and

a controller operable to control a vehicle, including the remote camera, according to a re-projected image.

16. The system of claim 15, wherein the graphics processing unit is further operable to warp each frame of digital video to approximate a geometry of a future video frame in real-time.

17. The system of claim 15, wherein the graphics processing unit is further operable to re-map the digital video frame to determine the original geometric image model corresponding to a field of view of the camera at the video frame capture time and to modify the original geometric image to approximate the real-time field of view of the camera at the video frame receive time to form the adjusted geometric image.

18. The system of claim 15, further comprising an application programming interface to control an attitude and runway alignment of an unmanned aerial vehicle using a displayed, re-projected image.

19. The system of claim 15, wherein the vehicle comprises an unmanned aerial vehicle.

20. The system of claim 19, wherein the vehicle comprises an inertial navigation system operable to provide a camera geometry for each recorded digital video frame at a time the frame is captured.