Main Face Choosing Device Stabilizes Subject Selection
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Solution Overview
Problem
Existing image capturing apparatuses experience frequent main face changeovers due to slight changes in the states of human figures, leading to unsightly image quality, as they primarily rely on position and reliability weights without adequately considering the stability of face detection over successive frames.
Innovation Solution
A main face choosing device and method that calculates priority weights based on face position and size, and uses a counter system to stabilize main face determination by incrementing counters for faces with higher priority values, preventing immediate changeovers unless a predetermined threshold is met, thus reducing frequent main face changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If main face choice is made based on face states (position and size) in captured images, then the main face selection adapts to current image content, but frequent main face changeover occurs due to slight changes in face states
Solution Approach 1:
The patent applies preliminary action by establishing a counter mechanism before main face determination. The counter accumulates priority values over multiple frames, and only when the counter reaches a predetermined threshold does the main face determination occur. This preliminary accumulation process filters out transient fluctuations in face states, allowing the system to adapt to genuine changes while ignoring minor variations, thus resolving the contradiction between adaptability and stability.
2Stability of the object's composition
If main face changeover is suppressed to reduce frequent changes, then image quality stability improves, but the ability to switch to the correct main face when conditions change deteriorates
Solution Approach 1:
The patent applies dynamics by making the main face determination threshold dynamic rather than fixed. The determination occurs when the counter value reaches a predetermined number, which effectively creates an adaptive threshold based on accumulated evidence. This dynamic approach allows the system to maintain stability during normal operation while automatically adapting when sufficient evidence accumulates, resolving the contradiction between stability and adaptability.
3Speed
If face detection relies on position and reliability weights, then detection speed is maintained, but detection stability over successive frames deteriorates
Solution Approach 1:
The patent applies continuity of useful action by continuously accumulating counter values across successive frames rather than making isolated determination decisions. The counter mechanism maintains a running total of priority values, ensuring that each frame's detection contributes to an ongoing evaluation process. This continuous accumulation provides temporal smoothing that enhances detection stability while maintaining processing speed, as the system evaluates accumulated evidence rather than making abrupt decisions based on single-frame data.
Data Source
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AI summary
An image capturing apparatus chooses a main face from among faces detected in successively captured images based on a degree of priority calculated for each detected face. Moreover, the image capturing apparatus compares the degree of priority assigned to the face corresponding to a last chosen main face and the degrees of priority assigned to the faces corresponding to faces other than the main face, and then counts the number of times the degrees of priority assigned to the faces corresponding to faces other than the main face exceed the degree of priority assigned to the face corresponding to the main face. When one of the number of times counted for the faces other than the main face exceeds a preset threshold value, the image capturing apparatus performs a main face changeover to the one of the faces.