Image Correction Device Using Frame Fluctuation Filtering
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Solution Overview
Problem
Conventional image capture devices face challenges in accurately correcting fixed pattern noise due to sudden frame fluctuations during the calculation of correction values, which affects the quality of the output image.
Innovation Solution
An image correction method and device that calculates a one-frame addition average value for image data at the time of light shielding, determines if it falls within a preset range, and only adds this data to a cumulative correction value if it does, thereby updating and storing it. After a specified number of updates, the cumulative correction value is divided to obtain a correction value, which is then subtracted from the image data to correct for fixed pattern noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cumulative correction value is calculated by continuously adding image data during light shielding, then correction accuracy improves, but sudden frame fluctuations cause degradation in correction quality
Solution Approach 1:
The patent introduces a feedback mechanism where the calculated one-frame addition average value is compared against a predetermined reference range. Based on this comparison feedback, the system determines whether to accumulate the current frame's data or discard it, thereby maintaining reliable correction quality while preserving accuracy through selective accumulation
Solution Approach 2:
The patent changes the parameter of data accumulation by introducing a conditional threshold-based selection mechanism. Instead of continuously accumulating all frame data, the system dynamically selects which frames to accumulate based on whether their addition average values fall within the predetermined range, thus preventing fluctuation-induced degradation
2Quantity of substance
If all image data during light shielding is accumulated for correction value calculation, then more correction data is obtained, but data quality deteriorates due to inclusion of fluctuating frames
Solution Approach 1:
The patent transforms the correction data accumulation process from unconditional to conditional by introducing a quality parameter check. The one-frame addition average value is calculated and compared against a predetermined range, and only frames meeting this quality criterion are accumulated, thus maintaining both sufficient quantity and high quality of correction data
Solution Approach 2:
The patent applies local quality control by evaluating each frame's addition average value independently against the predetermined range criterion. This allows the system to selectively accumulate high-quality frames while discarding low-quality fluctuating frames, ensuring that the correction data maintains high precision throughout the accumulation process
Data Source
AI summary
In an image correction method and an image capture device, a one-frame addition average calculation unit calculates a one-frame addition average value. If the one-frame addition average value falls within an appropriate range, a determination circuit inputs image data for one frame to an adder and the adder adds the image data to a cumulative correction value to update the correction value. The updated correction value is stored in a frame memory. If the one-frame addition average value is outside the appropriate range, the image data for one frame is discarded. After updating the cumulative correction value until the number of updates reaches a prescribed number, an FPN correction value is calculated by dividing the cumulative correction value stored in the frame memory by the prescribed number, and an image is corrected by subtracting the FPN correction value from the image data inputted at the time of imaging.