Multi-Rating Focus Evaluation for Consecutive Image Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image classification technologies, such as the one disclosed in Japanese Patent Laid-Open No. 2004-320487, fail to accurately select the intended focused image among a series of captured images, as they rely solely on autofocus evaluation values, which do not guarantee the object of interest is in focus, especially when objects move in depth, leading to inconsistent image quality due to varying object image magnification and spatial frequency characteristics.
Innovation Solution
An image processing system that evaluates focus states using multiple rating systems (primary and secondary ratings) based on focus detection results, correlating defocus amounts with specific ratings and adjusting the focus detection range thresholds to determine the appropriate rating mode, allowing for more accurate focus state assessment and selection of in-focus images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If autofocus evaluation value is used to select the best focused image, then automation is improved, but measurement precision deteriorates because the highest AF evaluation value does not guarantee the object of interest is in focus
Solution Approach 1:
The patent segments the evaluation process into multiple independent rating systems (primary rating based on AF evaluation value, secondary rating based on object distance, third rating based on spatial frequency). Each rating evaluates different aspects of focus quality, and the system integrates these segmented evaluations to make the final selection, thereby improving measurement precision while maintaining automation.
Solution Approach 2:
The patent changes the evaluation parameters from a single AF evaluation value to multiple parameters including AF evaluation value, object distance, and spatial frequency characteristics. By introducing additional evaluation parameters, the system achieves more accurate focus state assessment while maintaining automatic operation.
2Device complexity
If focus position is fixed during consecutive capturing, then device complexity is reduced, but manufacturing precision deteriorates because object image magnification varies when objects move in depth
Solution Approach 1:
The patent implements feedback mechanisms by detecting object distance and spatial frequency characteristics, then using this information to adjust the evaluation criteria. The system feeds back the varying magnification information to the rating process, allowing it to compensate for the fixed focus position limitation and maintain consistent image quality assessment.
Solution Approach 2:
The patent compensates for magnification variation by introducing object distance and spatial frequency as additional evaluation parameters. When objects move in depth causing magnification changes, the system adjusts the evaluation based on these parameter changes, maintaining image quality consistency without increasing focus control complexity.
3Measurement precision
If spatial frequency characteristic is used for focus evaluation, then measurement precision is improved, but device complexity increases due to additional processing requirements
Solution Approach 1:
The patent segments the image processing into distinct stages: initial AF evaluation, object distance detection, and spatial frequency analysis. Each segmentation handles a specific aspect of focus evaluation, allowing the system to achieve high measurement precision while managing device complexity through modular processing architecture.
Data Source
AI summary
An image processing apparatus includes a first evaluator configured to evaluate under a first evaluation condition a focus state of each of a plurality of image data acquired by consecutive capturing, a second evaluator configured to evaluate the focus state of each of the plurality of image data under a second evaluation condition different from the first evaluation condition, and a recorder configured to record first evaluation information indicating an evaluation result under the first evaluation condition and second evaluation information indicating an evaluation result under the second evaluation condition.