METHOD AND SYSTEM FOR FAST THREE-DIMENSIONAL IMAGING USING DEFOCUSING AND FEATURE RECOGNITION

• US 20110058740A1
• Filed: 11/19/2008
• Published: 03/10/2011
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Gharib, Morteza, Pereira, Francisco, Graff, Emilio
• Granted Patent: US 8,089,635 B2
• Time in Patent Office: Days
• US Class Current: 382/173
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures

Abstract

Described is a method and system for fast three-dimensional imaging using defocusing and feature recognition is disclosed. The method comprises acts of capturing a plurality of defocused images of an object on a sensor, identifying segments of interest in each of the plurality of images using a feature recognition algorithm, and matching the segments with three-dimensional coordinates according to the positions of the images of the segments on the sensor to produce a three-dimensional position of each segment of interest. The disclosed imaging method is “aware” in that it uses a priori knowledge of a small number of object features to reduce computation time as compared with “dumb” methods known in the art which exhaustively calculate positions of a large number of marker points.

Claims

1. A method for fast three-dimensional imaging using defocusing and feature recognition, comprising acts of:

capturing a plurality of defocused images of an object on a sensor;

identifying segments of interest in each of the plurality of defocused images using a feature recognition algorithm; and

matching the segments with three-dimensional coordinates according to the positions of the images of the segments on the sensor to produce a three-dimensional position of each segment of interest.

2. The method of claim 1, further comprising an act of ascertaining sub-pixel positions of the segment positions on the sensor using a cross-correlation type algorithm.

3. A data processing system for fast three-dimensional imaging using defocusing and feature recognition, comprising:

a sensor for capturing a plurality of defocused images of an object substantially simultaneously; and

one or more processors configured to perform operations of;

receiving a plurality of defocused images of an object captured on the sensor;

identifying segments of interest in each of the plurality of images using a feature recognition algorithm; and

matching the segments with three-dimensional coordinates according to the positions of the images of the segments on the sensor to produce a three-dimensional position of each segment of interest.

4. The data processing system of claim 3, further comprising a camera having a lens obstructed by a mask with a plurality of off-axis apertures, where the sensor is configured to capture a plurality of defocused images of an object by receiving a signal transmitted from the object through the plurality of off-axis apertures and through the lens.

5. The data processing system of claim 4, wherein the one or more processors are further configured to ascertain sub-pixel positions of the segment positions on the sensor using a cross-correlation type algorithm.

6. The data processing system of claim 3, wherein the one or more processors are further configured to ascertain sub-pixel positions of the segment positions on the sensor using a cross-correlation type algorithm.

7. A computer program product for fast three-dimensional imaging using defocusing and feature recognition, the computer program product comprising computer-readable instruction means stored on a computer-readable medium that are executable by a computer having a processor for causing the processor to perform operations of:

receiving a plurality of defocused images of an object on a sensor;

identifying segments of interest in each of the plurality of images using a feature recognition algorithm; and

matching the segments with three-dimensional coordinates according to the positions of the images of the segments on the sensor to produce a three-dimensional position of each segment of interest.

8. The computer program product of claim 7, further comprising instruction means for causing a processor to ascertain sub-pixel positions of the segment positions on the sensor using a cross-correlation type algorithm.