Method and apparatus for controlling classification and classification switching in a vision system

• US 20050185846A1
• Filed: 02/24/2004
• Published: 08/25/2005
• Est. Priority Date: 02/24/2004
• Status: Active Grant

• Current Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Luo, Yun, Wallace, Jon K., Khairallah, Farid
• Granted Patent: US 7,636,479 B2
• Time in Patent Office: Days
• US Class Current: 382/224
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/262 using context analysis, e.g. lexical, syntactic or semantic context
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands

Abstract

A system for classifying image data includes a vision system (58) for continuously imaging an area (42) of interest and providing an image signals. A classifier (84) determines an image class corresponding to each image signal, determines a confidence level for each determined image class, determines a time period for the confidence level, and establishes an image classification in response thereto. Switching between image classifications is in response to the confidence level and time period of the confidence level. When used in a vehicle restraining system (20), other monitor vehicle parameters (54) can be used to adjust the confidence levels and time periods needed to switch between image classifications.

Claims

1. An occupant classification method comprising the steps of:

continuously imaging an area of interest and providing image signals;

determining an image class corresponding to each image signal;

determining a confidence level for each determined image class;

determining a time period of a determined image class at a determined confidence level; and

establishing an image classification in response to the determined confidence level and time period.

2. The method of claim 1 further comprising the steps of:

further monitoring the image signals;

determining if a further monitored image signal indicates a different class;

switching the established image classification to a new established image classification in response to predetermined switching confidence level for a predetermined switching time period.

3. The method of claim 2 wherein the system is used in a vehicle restraining system and further comprises the steps of:

monitoring vehicle input signals;

adjusting the switching time period and switching confidence level in response to said monitored vehicle input signals.

4. The method of claim 3 wherein said step of monitoring vehicle input signals includes monitoring an open condition of a vehicle door.

5. The method of claim 3 wherein said step of monitoring vehicle input signals includes monitoring a condition of the vehicle ignition.

6. The method of claim 1 wherein the step of imaging includes using a stereo camera.

7. The method of claim 1 wherein the step of imaging further includes the step of removing background information and noise from the image signal.

8. The method of claim 7 wherein the step of removing background information and noise includes applying a contrast limited adaptive histogram equalization that adjusts the image for lighting conditions.

9. The method of claim 1 wherein the step of determining an image class uses at least one of a support vector machine and a neural network.

10. A method for controlling classification of image data comprising the steps of:

imaging an area of interest and providing image data;

classifying the image data as one of a plurality of possible classes; and

filtering the classification of the image data in response to a characteristic of the classification.

11. The method of claim 10 wherein the step of classifying includes determining a confidence level and time period of the confidence level.

12. The method of claim 11 wherein the step of filtering includes switching classifications of image data in response to the determined confidence level and time period compared to a confidence level switching threshold and a time period switching threshold, respectively.

13. A system for classifying image data comprising:

a vision system for continuously imaging an area of interest and providing image signals; and

a classifier for determining an image class corresponding to each image signal, determining a confidence level for each determined image class, determining a time period for the confidence level, and establishing an image classification in response to the confidence level and time period of the confidence level.

14. A system for classifying image data associated with a vehicle occupant safety system into an associated one of a plurality of output classes, said system comprising:

a vision system that images a vehicle interior to provide an image signal; and

a classifier for determining an image class in response to a class confidence level of the image signal and time period of the classification, said classifier permitting class switching only in response to a new image class determination having a predetermined new confidence value for a predetermined time period.

15. The system of claim 14 wherein the vision system comprises a stereo vision system that produces three-dimension image data of the vehicle interior as a stereo disparity map.