Systems and Methods for Detecting a Tilt Angle from a Depth Image

• US 20120163669A1
• Filed: 03/06/2012
• Published: 06/28/2012
• Est. Priority Date: 05/01/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Mathe, Zsolt, Marais, Charles Claudius
• Granted Patent: US 8,290,249 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/20 Image preprocessing
• CPC Class Codes: G06V 10/40 Extraction of image or video features
• CPC Class Codes: G06V 20/64 Three-dimensional objects
• CPC Class Codes: G06V 40/103 Static body considered as a whole, e.g. static pedestrian or occupant recognition
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body

Abstract

A depth image of a scene may be received, observed, or captured by a device. A human target in the depth image may then be scanned for one or more body parts such as shoulders, hips, knees, or the like. A tilt angle may then be calculated based on the body parts. For example, a first portion of pixels associated with an upper body part such as the shoulders and a second portion of pixels associated with a lower body part such as a midpoint between the hips and knees may be selected. The tilt angle may then be calculated using the first and second portions of pixels.

Claims

1. A device, the device comprising:

a camera component, wherein the camera component receives a depth image of a scene; and

a processor, wherein the processor executes computer executable instructions, and wherein the computer executable instructions comprise instructions for;

receiving the depth image from the camera component;

scanning a human target in the depth image; and

calculating a tilt angle based on the scanned human target.

2. The device of claim 1, wherein the instructions for scanning the human target in the depth image comprise instructions for determining a location and a measurement of one or more body parts of the human target.

3. The device of claim 2, wherein the location of the one or more body parts comprises a location and a measurement of shoulders of the human target, a location and measurement of hips of the human target, and a location and a measurement of knees of the human target.

4. The device of claim 3, wherein the instructions for calculating the tilt angle based on the scanned human target further comprise instructions for:

selecting a first portion of pixels of the human target based on the location of the shoulders; and

selecting a second portion of pixels of the human target based a midpoint between the location of the hips and knees.

5. The device of claim 4, wherein each of the pixels in the first portion and second portion of pixels has a depth value associated therewith.

6. The device of claim 5, wherein the instructions for calculating the tilt angle based on the scanned human target further comprise instructions for calculating a first value associated with a vertical distance between the first and second portions.

7. The device of claim 6, wherein the instructions for calculating the tilt angle based on the scanned human target further comprise instructions for:

calculating a first average depth value using the depth value for each pixel in the first portion;

calculating a second average depth value using the depth value for each pixel in the second portion;

subtracting the second average depth value from the first average depth value to calculate a second value.

8. The device of claim 7, wherein the instructions for calculating the tilt angle based on the scanned human target further comprise instructions for:

calculating an arctangent of the second value divided by the first value to determine the tilt angle.

9. A computer-readable storage medium having stored thereon computer executable instructions for detecting a tilt, the computer executable instructions comprising instructions for:

receiving the depth image from the camera component;

scanning a human target in the depth image to determine a location of at least an upper body part and a lower body part; and

calculating a tilt angle using the upper body part and the lower body part.

10. The computer-readable storage medium of claim 9, wherein the upper body part comprises shoulders of the human target and the lower body part comprises a midpoint between the hips and the knees of the human target.

11. The computer-readable storage medium of claim 9, wherein the instructions for calculating the tilt angle using the upper body part and the lower body part further comprise instructions for:

identifying a first portion of pixels of the human target at the location of the upper body part; and

identifying a second portion of pixels of the human target at the location of the lower body part.

12. The computer-readable storage medium of claim 11, wherein each of the pixels in the first portion and second portion of pixels has a depth value associated therewith.

13. The computer-readable storage medium of claim 12, wherein the instructions for calculating the tilt angle using the upper body part and the lower body part further comprise instructions for calculating a first value associated with a vertical distance between the first and second portions.

14. The computer-readable storage medium of claim 13, wherein the instructions for calculating the tilt angle using the upper body part and the lower body part further comprise instructions for:

calculating a first average depth value using the depth value for each pixel in the first portion;

calculating a second average depth value using the depth value for each pixel in the second portion;

subtracting the second average depth value from the first average depth value to calculate a second value.

15. The computer-readable storage medium of 14, wherein the instructions for calculating a tilt angle using the location of the upper body part and the lower body part further comprise instructions for:

calculating an arctangent of the second value divided by the first value to determine the tilt angle.

16. A system for detecting a tilt, the system comprising:

a capture device, wherein the capture device comprises a camera component that receives a depth image of a scene, wherein the depth image comprises a human target associated with a user; and

a computing device in operative communication with the capture device, wherein the computing device comprises a processor that receives the depth image from the capture device, determines a location of an upper body part and a lower body part of human target in the depth image, selects a first portion of pixel of the human target associated with the upper body part and a second portion of pixels of the human target associated with the lower body part, and calculates a tilt angle using the first portion of pixels and the second portion of pixels.

17. The system of claim 16, wherein each of the pixels in the first portion and second portion of pixels has a depth value associated therewith.

18. The system of claim 17, wherein processor further calculates a tilt angle using the first portion of pixels and the second portion of pixels by calculating a first value associated with the vertical distance between the first and second portions.

19. The system of claim 18, wherein processor further calculates a tilt angle using the first portion of pixels and the second portion of pixels by:

calculating a first average depth value using the depth value for each pixel in the first portion;

calculating a second average depth value using the depth value for each pixel in the second portion;

subtracting the second average depth value from the first average depth value to calculate a second value.

20. The system of 19, wherein processor further calculates a tilt angle using the first portion of pixels and the second portion of pixels by:

calculating an arctangent of the second value divided by the first value to determine the tilt angle.