Dynamic Face Detection Threshold for Varying Shooting Scenes

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Solution Overview

Problem

Existing image pickup systems use a fixed threshold for face detection, which is not suitable for varying shooting scenes, such as business portraits and group photographs, leading to inconsistent face recognition accuracy.

Innovation Solution

An image processing apparatus and method that allows users to set and adjust the face detection threshold based on the specific shooting scene, enabling tailored face region detection for different photography scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed threshold of detection likelihood is used for face region detection, then the detection process is simple and fast, but the face recognition accuracy deteriorates when applied to different shooting scenes

Engineering Contradiction:
Improveface detection speedVSAvoidface recognition accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the detection threshold variable rather than fixed. The threshold is dynamically adjusted based on the shooting scene type (e.g., business portrait, group photograph, close-up), allowing the system to optimize face detection accuracy for different scenarios while maintaining reasonable processing speed through automated threshold selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of detection threshold based on shooting scene characteristics. Different shooting scenes have different requirements for face detection sensitivity, and the system modifies the threshold parameter accordingly to balance between detection accuracy and processing efficiency for each specific scene type.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a high threshold of detection likelihood is used, then face recognition accuracy for business portraits is improved, but the ability to detect all persons in group photographs deteriorates

Engineering Contradiction:
Improveface recognition accuracyVSAvoidadaptability to different shooting scenes
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by tailoring the detection threshold to specific local contexts (shooting scenes). Instead of using a single uniform threshold for all scenarios, the system selects different threshold values appropriate for each shooting scene type, such as higher thresholds for business portraits where accuracy is critical and lower thresholds for group photographs where completeness is prioritized.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adapts the detection threshold based on the identified shooting scene. The threshold is not static but changes according to the photographic context, enabling the same detection system to optimize for different objectives across various shooting scenarios without manual intervention.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If a low threshold of detection likelihood is used, then the ability to detect all persons in group photographs is improved, but face recognition accuracy for business portraits deteriorates

Engineering Contradiction:
Improvedetection completeness for group photosVSAvoidface recognition accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by selecting different threshold levels appropriate for each shooting scene type. For group photographs, a lower threshold is used to ensure all persons are detected even if individual face quality varies. For business portraits, a higher threshold ensures only high-quality face detections are made, filtering out false positives.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS8797416B2Image processing apparatus and image processing method
Publication Date: 2014.08.05 CANON KK
  • US8797416B2 patent drawing
  • US8797416B2 patent drawing
  • US8797416B2 patent drawing

AI summary

In an image processing apparatus, a shooting scene and shooting parameters for each image pickup apparatus that is to be used to pick up an image are set in accordance with a user input. A picked-up image is received from an image pickup apparatus. In accordance with the shooting scene that is set for the image pickup apparatus which has picked up the received image, a threshold of the likelihood of detecting a face region that is included in the shooting parameters for the shooting scene is obtained. A face region is detected from the picked-up image using the obtained threshold of the likelihood of detecting a face region. An image of the detected face region is highlighted and displayed on a display screen.