DEPTH-BASED GAIN CONTROL

• US 20110134114A1
• Filed: 12/02/2010
• Published: 06/09/2011
• Est. Priority Date: 12/06/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: PrimeSense Ltd (Apple Inc.)
• Inventors: Sali, Erez, Rais, Dmitry, Cohen, Daniel
• Granted Patent: US 8,830,227 B2
• Time in Patent Office: Days
• US Class Current: 345/419
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects

Abstract

A method for depth mapping includes capturing an electronic image of a scene using an imaging device. The electronic image is processed to generate depth data with respect to the scene. The gain of the imaging device is set responsively to the depth data.

Claims

1. A method for depth mapping, comprising:

capturing an electronic image of a scene using an imaging device;

processing the electronic image to generate depth data with respect to the scene; and

setting a gain of the imaging device responsively to the depth data.

2. The method according to claim 1, wherein capturing the electronic image comprises projecting a pattern of optical radiation onto the scene, and wherein processing the electronic image comprises computing the depth data based on transverse shifts of the pattern in the image.

3. The method according to claim 1, wherein processing the electronic image comprises creating and outputting a depth map of the scene.

4. The method according to claim 3, wherein setting the gain comprises extracting a representative depth value from the depth map, and selecting the gain responsively to the representative depth value.

5. The method according to claim 4, wherein extracting the representative depth value comprises computing a histogram of the depth data in the depth map, and selecting the representative depth value based on a set of high-frequency bins in the histogram.

6. The method according to claim 1, wherein setting the gain comprises selecting a pre-calibrated gain value based on the depth data.

7. The method according to claim 6, and comprising, prior to capturing the electronic image of the scene, computing gain calibration data by capturing and processing multiple images of a calibration object placed at different, respective distances from the imaging device, wherein the pre-calibrated gain value is selected based on the gain calibration data.

8. Apparatus for depth mapping, comprising:

an imaging device, which is configured to capture an electronic image of a scene; and

a processor, which is configured to process the electronic image in order to generate depth data with respect to the scene, and to set a gain of the imaging device responsively to the depth data.

9. The apparatus according to claim 8, wherein the imaging device is configured to project a pattern of optical radiation onto the scene, and wherein the processor is configured to compute the depth data based on transverse shifts of the pattern in the image.

10. The apparatus according to claim 8, wherein the processor is configured to create and output a depth map of the scene, comprising the depth data, based on the electronic image.

11. The apparatus according to claim 10, wherein the processor is configured to extract a representative depth value from the depth map, and to select the gain responsively to the representative depth value.

12. The apparatus according to claim 11, wherein the processor is configured to compute a histogram of the depth data in the depth map, and to select the representative depth value based on a set of high-frequency bins in the histogram.

13. The apparatus according to claim 8, wherein the processor is configured to set the gain by selecting a pre-calibrated gain value based on the depth data.

14. The apparatus according to claim 13, wherein prior to capturing the electronic image of the scene, gain calibration data are computed by capturing and processing multiple images of a calibration object placed at different, respective distances from the imaging device, wherein the processor is configured to select the pre-calibrated gain value based on the gain calibration data.