Autofocus Area Selection for Moving Objects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing autofocus mechanisms in cameras fail to effectively focus on rapidly moving and unpredictable subjects, particularly in dynamic scenes, leading to suboptimal image capture results.
Innovation Solution
An automatic autofocus area selection system that utilizes consecutive aligned two-frame image difference information to detect moving objects and apply encoded rules for selecting the most likely AF area, prioritizing the face when present, and adjusts the lens focus using depth sensing or image contrast methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional autofocus mechanisms are used, then the system is simple to operate, but it fails to effectively focus on rapidly moving and unpredictable subjects
Solution Approach 1:
The system performs preliminary actions by detecting moving objects and selecting autofocus areas in advance based on motion detection from consecutive frames. This allows the autofocus mechanism to be pre-positioned on moving subjects before the actual capture, improving reliability for dynamic scenes without requiring complex real-time adjustment mechanisms
Solution Approach 2:
The system implements feedback by continuously analyzing motion information from consecutive image frames and adjusting the autofocus area selection based on detected object movement. This feedback loop enables the system to adapt to rapidly moving subjects while maintaining manageable complexity through algorithmic control
2Reliability
If a fixed focus box is used in the center of the field of view, then the autofocus mechanism is simple, but it cannot track moving objects that leave the center area
Solution Approach 1:
The system applies dynamics by transitioning from a static fixed focus box to a dynamic autofocus area that automatically relocates based on detected moving objects. The focus area becomes dynamic, following the motion of subjects across the field of view, which improves tracking capability while using motion detection algorithms rather than complex mechanical adjustments
Solution Approach 2:
The autofocus system performs self-service by automatically detecting moving objects and selecting appropriate focus areas without requiring manual intervention. The system serves itself by using its own captured image data to guide the autofocus mechanism, eliminating the need for external control while maintaining simple operation for the user
3Reliability
If continuous autofocus mechanisms are used to lock onto subjects, then moving objects can be tracked, but the system provides less than desirable results for intensive and unpredictably moving subjects
Solution Approach 1:
The system performs preliminary motion analysis by examining consecutive image frames to predict where moving objects will be positioned. This preliminary action allows the autofocus mechanism to be proactively positioned on fast-moving subjects before they move out of focus, improving both stability and precision for unpredictable motion patterns
Solution Approach 2:
The system uses feedback from continuous motion detection to dynamically adjust the autofocus area selection. By analyzing the motion trajectories of detected objects across multiple frames, the system provides feedback-driven adjustments that maintain focus accuracy on unpredictable subjects while managing the complexity through algorithmic control
Data Source
AI summary
An improved mechanism for image area selection upon which autofocusing is directed during image capture on a digital image capture device, such as a camera or cellular phone. This image area selection provides accurate selection of moving object even when the objects being focused upon are subject to intense or unpredictable motion. The image area selection is performed based on alignment of consecutive frames (images) for which a rough foreground mask, and moving object mask have been determined. Differences between these frames are utilized to determine a moving object contour, which also provides feedback through a delay to the moving object detection step.