Dynamic Defect Map Update for Radiographic Imaging Dark Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Imaging devices face challenges in correcting defective pixels due to changes in behavior caused by the accumulation state of electric charges from dark current, as existing methods do not dynamically adapt to these changes, leading to increased processing time and degraded image quality.
Innovation Solution
An image processing apparatus that obtains information on defective pixels based on characteristic output fluctuations caused by the accumulation state of electric charges, allowing for dynamic defect correction by generating a defect map and using it to identify and correct defective pixels in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If defect correction is performed using fixed defect maps obtained at manufacturing time, then processing time is reduced and manufacturing simplicity is maintained, but image quality deteriorates because pixels that behave defectively change according to the accumulation state of electric charges by dark current
Solution Approach 1:
The patent applies dynamics by transitioning from fixed defect maps to dynamic defect maps that are updated based on the accumulation state of electric charges. The system determines the accumulation state of dark current and selectively updates defect maps accordingly, allowing the defect correction to adapt to changing pixel behaviors over time while maintaining efficient processing through conditional updates rather than continuous reprocessing
Solution Approach 2:
The patent changes the parameter of defect map temporal validity by introducing accumulation state thresholds. When the accumulation state of electric charges exceeds a predetermined threshold, the system determines that the defect map should be updated. This parameter-based approach allows the system to maintain fixed defect maps during stable conditions (reducing processing time) while updating them when necessary (maintaining image quality)
2Reliability
If defect correction is performed by interpolating from surrounding pixels for all suspected defective pixels, then image quality is maintained, but processing time increases due to dynamic analysis of each pixel's accumulation state
Solution Approach 1:
The patent applies local quality by performing detailed dynamic analysis only on pixels located at defect map update positions rather than all pixels in the image. The system identifies specific regions where accumulation state changes have occurred and applies interpolation correction only to those local areas, while other regions use the existing defect map data, thus maintaining image quality where needed while preserving overall processing speed
3Measurement precision
If dark correction is performed immediately after obtaining a dark image, then fixed pattern noise is effectively removed, but defective pixels may be misidentified because the accumulation state of electric charges has not yet stabilized
Solution Approach 1:
The patent applies preliminary action by performing an initial dark correction to remove fixed pattern noise, then subsequently determining the accumulation state of electric charges before finalizing defect identification. The system uses the initial dark-corrected image combined with accumulation state analysis to accurately identify defective pixels, ensuring that correction is not performed on pixels that may still be stabilizing
Solution Approach 2:
The patent uses feedback by continuously monitoring the accumulation state of electric charges and using this information to adjust defect map update timing. The accumulation state determination feeds back into the defect correction process, allowing the system to adapt its defect identification strategy based on the actual charge accumulation conditions, thereby improving both dark correction accuracy and defect detection reliability
Data Source
AI summary
Information indicating at least one defective pixel in an imaging device for obtaining a radiographic image, based on characteristic information indicating an output fluctuation of each pixel caused by an accumulation state of an electric charge by a dark current in the imaging device. The radiographic image is corrected based on the information indicating the defective pixel.