Foreground-Aware Background Estimation for Video Object Detection

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Solution Overview

Problem

Traditional background estimation methods in video-based object tracking struggle to adapt quickly to changes in the scene, such as lighting or environment, and often absorb stationary foreground objects into the background model, especially when the learning rate is not optimally chosen.

Innovation Solution

A system and method for foreground-aware background estimation using a video acquisition module, fit test module, and foreground-aware background model update module, which updates the background model only for pixels not containing foreground objects, employing Gaussian mixture models to adjust weights and parameters based on incoming pixel values, thus preventing foreground objects from being absorbed into the background.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional background estimation methods are used with a fixed learning rate, then the model can adapt to scene changes, but stationary foreground objects are absorbed into the background model

Engineering Contradiction:
Improveadaptation to scene changesVSAvoidforeground object detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies dynamics by making the learning rate adaptive rather than fixed. The learning rate automatically adjusts based on foreground detection results - reducing when foreground objects are detected to prevent absorption, and increasing when only background changes occur to accelerate adaptation. This dynamic adjustment resolves the contradiction between adapting to scene changes and preventing foreground absorption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback by using foreground detection outcomes to modulate the learning rate. The detected foreground mask feeds back into the background estimation process, creating a closed-loop system where the learning rate is continuously adjusted based on whether foreground objects are present, thereby preventing absorption while maintaining adaptation capability.

Inventive Principle:
Principle #23Feedback

2Speed

If a fast learning rate is used for quick adaptation to scene changes, then the model responds rapidly to lighting and environment changes, but stationary objects are quickly absorbed into the background

Engineering Contradiction:
Improveadaptation speedVSAvoidforeground object preservation
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The learning rate transitions from a static parameter to a dynamic one that responds in real-time to scene conditions. When rapid adaptation is needed (e.g., lighting changes), the system allows faster learning rates, but when foreground objects are detected, it automatically reduces the learning rate to preserve them, thus resolving the speed-reliability contradiction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system takes preliminary anti-action by detecting foreground objects before they can be absorbed into the background model. By identifying foreground pixels in advance and reducing the learning rate proactively, the system prevents absorption before it occurs, maintaining both fast adaptation capability and foreground object integrity.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If a slow learning rate is used to prevent foreground absorption, then stationary objects are preserved, but the model cannot adapt quickly to scene changes

Engineering Contradiction:
Improveforeground object preservationVSAvoidresponse to scene changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

Rather than using a consistently slow learning rate, the system dynamically adjusts the learning rate based on scene conditions. When no foreground objects are present, a faster learning rate enables quick adaptation to background changes. When foreground objects are detected, the learning rate slows down to preserve them, thus achieving both preservation and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The feedback mechanism monitors foreground presence and adjusts the learning rate accordingly. This closed-loop control allows the system to maintain slow learning rates only when necessary (when foreground objects are detected), while permitting faster rates during pure background adaptation, thereby resolving the contradiction between preservation and adaptability.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If the learning rate is optimized for one speed range, then detection accuracy is improved for that range, but performance degrades for other speeds

Engineering Contradiction:
Improvedetection accuracyVSAvoidspeed range support
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system replaces a fixed learning rate optimized for a specific speed range with a dynamic learning rate that adapts to different scenarios. This allows the system to maintain high detection accuracy across a wide range of object speeds and scene change rates, rather than being optimized for a narrow range, thus resolving the precision-versus-versatility contradiction.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS9767570B2Systems and methods for computer vision background estimation using foreground-aware statistical models
Publication Date: 2017.09.19 CONDUENT BUSINESS SERVICES LLC
  • US9767570B2 patent drawing
  • US9767570B2 patent drawing
  • US9767570B2 patent drawing

AI summary

Systems and methods are disclosed for background modeling in a computer vision system for enabling foreground object detection. A video acquisition model receives video data from a sequence of frames. A fit test module identifies a foreground object from the video data and defines a foreground mask representative of the identified foreground object. A foreground-aware background estimation module defines a first background model from the video data and then further defines an updated background model from an association of a current frame of the video data, the first background model and the foreground mask.