Perspective improvement for image and video applications

• US 7,742,624 B2
• Filed: 04/25/2006
• Issued: 06/22/2010
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Augustine, Bruce A., Thiems, Michael S., Super, Boaz J., Crenshaw, James E., Groat, Evan A.
• Primary Examiner(s): Bali; Vikkram
• Assistant Examiner(s): CHU, RANDOLPH I
• Application Number:
  US11/380,196
• Publication Number:
  US 20070248281A1
• Time in Patent Office: 1,519 Days
• Field of Search: 382/100, 382/106, 356/3, 348/208.15, 34833301-33304, 34824099-24003, 348143-160
• US Class Current: 382/106
• CPC Class Codes: G06V 10/247 by affine transforms, e.g. correction due to perspective effects; Quadrilaterals, e.g. trapezoids
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation

Abstract

A system and method for reducing distance-based distortion in a camera image of an object, where the distanced-based distortion is due to differences in distance from the camera to different parts of the object. In one approach, the distortion is reduced by estimating distances to different parts of the object and then generating a reprojected image of the object dependent upon the estimated distances and upon a virtual viewpoint that is more distant than the camera from the object. In a further approach, the image is warped such that points in the image match corresponding points in one or more stored templates. In a still further approach, if excessive distortion is present in the image, the camera zoom is increased and a magnified image is displayed, prompting a person to move farther from the camera thereby reducing the distortion.

Claims

1. A method for reducing distance-based distortion in an image of a face of a person, the image being captured by a camera, where the distance-based distortion is due to differences in distance from the camera to different parts of the face, the method comprising:

capturing an image of the face;

determining a distance to the face;

determining that a person is too close to the camera;

increasing a zoom of the camera based on the determined that the person is too close to the camera;

obtaining a zoomed image of the face; and

displaying the zoomed image of the face to the person in an attempt to get the person to move farther from the camera.

2. A method in accordance with claim 1, further comprising:

detecting the region of the face in the image; and

zooming the camera to the region of the face.

3. A method in accordance with claim 1, further comprising:

detecting the region of the face in the image; and

increasing the zoom if the region of the face is smaller than a predetermined size.

4. A system for reducing distance-based distortion in an image of a face of a person, the system comprising:

a camera capturing an image of the face;

a display unit displaying the image of the face to the person in an image frame; and

a processor determine that a person is too close to a camera, increase a zoom of the camera based on the determined that the person is too close to the camera, obtaining a zoomed image of the face, and displaying on the display unit, the zoomed image of the face to the person in an attempt to get the person to move farther from the camera.

5. A system in accordance with claim 4, further comprising a distance measuring system to measure the distance from the face to the camera.

6. A system in accordance with claim 4, further comprising a communication circuit to transmit the image to a device at a remote location.

7. A system in accordance with claim 4, wherein the camera is a video camera and further comprising a communication circuit to transmit video images to a device at a remote location.