Method and apparatus for automatically acquiring facial, ocular, and iris images from moving subjects at long-range

Patent metadata

Field	Value
Publication number	US-10178290-B2
Application number	US-201113029911-A
Country	US
Kind code	B2
Filing date	Feb 17, 2011
Priority date	Feb 17, 2010
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

The present invention relates to a method and apparatus for long-range facial and ocular acquisition. One embodiment of a system for acquiring an image of a subject's facial feature(s) includes a steerable telescope configured to acquire the image of the facial feature(s), a first computational imaging element configured to minimize the effect of defocus in the image of the facial feature(s), and a second computational imaging element configured to minimize the effects of motion blur. In one embodiment, the detecting, the acquiring, the minimizing the effect of the motion, and the minimizing the effect of the defocus are performed automatically without a human input.

First claim

What is claimed is:

1. A system for acquiring an image of a facial feature of a subject, the system comprising:
a source of spatially incoherent illumination comprising multiple emitters;
a stationary diffuser for diffusing and expanding the spatially incoherent illumination to produce diffused illumination;
a steerable telescope positioned to receive the diffused illumination from the diffuser and to collimate the diffused illumination into a beam directed at the facial feature, wherein the steerable telescope includes a low-resolution sensor configured to create an image of the subject's face and a high-resolution sensor configured to acquire the image of the facial feature, wherein the low-resolution sensor and the high-resolution sensor are both exposed by the same light source and share the same field of view;
a first computational imaging element configured to minimize an effect of defocus in the image of the facial feature;
a second computational imaging element configured to minimize an effect of motion blur in the image of the facial feature; and
a gaze monitor for identifying a location of the facial feature and for tracking a gaze angle of the subject in a continuous manner including when the subject is looking in a direction other than at the steerable telescope and during an acquisition of the image, wherein the tracking is based on a position of glint relative to a pupil of the subject.

2. The system of claim 1 , further comprising: a subject tracker for detecting the subject and guiding steerable telescope to focus on the subject.

3. The system of claim 2 , wherein the subject tracker is a three-dimensional stereo-based camera.

4. The system of claim 2 , further comprising a range finder for refining image motion and range motion measurements made by the subject tracker.

5. The system of claim 1 , wherein a source of spatially incoherent illumination is a trigger-pulsed, speckle-free light source and the steerable telescope includes a Fresnel lens for collimating diffused illumination.

6. The system of claim 5 , wherein the source of spatially incoherent illumination is a pulsable array of Vertical Cavity Surface Emitting Lasers (VCSELs).

7. The system of claim 1 , further comprising:
a three-dimensional trajectory generator comprising logic controls to determine where to aim the steerable telescope; and
an executable program to generate trajectory predictions of a plurality of facial features of the subject, the plurality of facial features including an ocular region and pupils, within a field of view of the steerable telescope.

8. The system of claim 1 , wherein the computing device is to determine a gaze angle by measuring the position of glint relative to a circumference of a pupil of the subject, and wherein the computing device is to identify the pupil based on a brightness of a retinal reflection and an existence of a symmetric pair with respect to a symmetry axis of a face of the subject.

9. The system of claim 1 , wherein the first computational imaging element comprises an optical element.

10. The system of claim 9 , wherein the optical element comprises a micro-lens array.

11. The system of claim 10 , wherein the second computational imaging element uses a sweep of an independent optical element.

12. The system of claim 1 , wherein the computing device is to monitor for eye glint and use the eye glint to detect the subject's gaze.

13. The system of claim 12 , wherein the computing device is to monitor for eye glint by observing a position of a specularly reflected near-infrared beam emitted by the light source.

14. The system of claim 1 , wherein the computing device is to control the image capture device to perform a focal sweep using a trajectory generated as a result of the tracking of the motion of the subject.

15. The system of claim 1 , wherein the computing device is to initiate the coordination of the (i) control of the image capture device to capture a high resolution image of the subject's iris with (ii) control of the light source to emit a short duration high per-pulse energy light emission automatically in response to the gaze analysis indication that the subject is looking at the image capture device.

16. The system of claim 1 , wherein when the gaze analysis indicates that the subject is looking at the image capture device, the computing device is to control the light source to emit a single short duration high energy light emission.

17. A system for acquiring an image of a facial feature of a subject, the system comprising:
a steerable telescope having a low-resolution sensor configured to create an image of the subject's face and a high-resolution sensor configured to acquire the image of the facial feature, wherein the low-resolution sensor and the high-resolution sensor are both exposed by the same light source and share the same field of view;
a high-repetition strobe synchronized with the steerable telescope for creating a glint in an ocular region of the subject; and
a gaze monitor-for tracking a gaze angle of the subject based on a position of the glint relative to a center of a pupil of the subject, and for identifying when the gaze angle indicates that the subject is looking at the steerable telescope-during an acquisition of the image, wherein the tracking is performed in a continuous manner, including when the subject is looking in a direction other than at the steerable telescope.

Assignees

• Stoker David
• Cowan Cregg
• Agrawal Motilal
• Van Der Laan Jan Edward
• Burns John Brian
• Stanford Res Inst Int

Inventors

• Stoker David
• Cowan Cregg
• Agrawal Motilal
• Van Der Laan Jan Edward
• Burns John Brian

Classifications

• G06V40/19

  Sensors therefor · CPC title

• G06V10/147

  Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19) · CPC title

• H04N23/45

  for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images · CPC title

• H04N7/18 Primary

  Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast · CPC title

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title