Sequential Camera Exposure Control for Body and Face Luminance

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Solution Overview

Problem

Existing technologies struggle to determine exposure suitable for partial detection of a subject, particularly when detecting human body or face regions, leading to issues such as underexposure or overexposure.

Innovation Solution

An information processing apparatus that includes units for detecting subjects and parts of subjects, determining exposure based on luminance differences to minimize luminance discrepancies between the subject and target luminance, and adjusting exposure accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If exposure is determined based on the luminance of the entire subject, then the overall luminance of the subject is optimized, but the luminance of specific parts (e.g., face) may be inappropriate

Engineering Contradiction:

Improveexposure accuracy for subject partsVSAvoiddetection and processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the subject detection into two distinct parts: detecting the entire subject (human body) and detecting specific parts (face). This segmentation allows the system to apply different exposure target luminances to different regions, optimizing exposure accuracy for both the overall subject and critical parts simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different exposure target luminances to different parts of the subject. Specifically, a first exposure target luminance is applied to the entire subject while a second exposure target luminance is applied to specific parts like the face. This local quality approach ensures that each region receives appropriate exposure treatment based on its specific requirements.

Inventive Principle:

Principle #3Local quality

2Reliability

If exposure is adjusted to optimize face region luminance, then face detection accuracy improves, but the overall subject luminance may become inappropriate

Engineering Contradiction:

Improvedetection accuracy of subject partsVSAvoidexposure accuracy for overall subject

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements a dynamic exposure determination process that operates in two sequential stages. First, exposure is determined based on the entire subject's luminance. Then, the system checks whether specific parts are detected and adjusts exposure based on those parts' luminance. This dynamic, multi-stage approach allows the system to adapt exposure settings based on detection results, ensuring both overall subject and specific parts achieve appropriate luminance levels.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12452541B2Information processing apparatus, imaging apparatus, method, and storage medium for determining exposure appropriate for partial detection of a subject

Publication Date: 2025.10.21 CANON KK

AI summary

An information processing apparatus includes an acquisition unit that acquires a captured image, a first detection unit that detects a subject from the image acquired by the acquisition unit, a second detection unit that detects a part of the subject from the image acquired by the acquisition unit, and a determination unit that determines exposure based on a luminance of the subject detected by the first detection unit to decrease a difference between the luminance of the subject and a first luminance which is a target luminance of the subject, and subsequently determines exposure based on a luminance of the part of the subject detected by the second detection unit to decrease a difference between the luminance of the part of the subject and a second luminance which is a target luminance of the part of the subject, the second luminance being different from the first luminance.