Image Sensor RTS Noise Correction via Adaptive Pixel Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image sensors face challenges in correcting blinking defect noise, specifically random telegraph signal (RTS) noise, which affects pixel values and reduces image quality due to shared read-out circuits, leading to increased noise and decreased sensitivity.
Innovation Solution
An image processing apparatus and method that acquires noise information associating pixel values with positional information and feature data, determines the occurrence of RTS noise, calculates candidate values for correction, and applies these values to correct pixel values, thereby addressing the RTS noise issue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a sharing pixel structure is used to reduce circuit area and enhance aperture ratio, then sensitivity is improved, but noise increases due to shared read-out circuits
Solution Approach 1:
The patent detects RTS noise characteristics in advance by capturing multiple dark images and analyzing pixel value variations. The system pre-identifies pixels prone to RTS noise and stores their characteristics, enabling corrective action to be taken when such pixels are encountered in actual imaging, thereby mitigating the noise issue while maintaining the sharing pixel structure's sensitivity benefits
Solution Approach 2:
The patent converts the harmful RTS noise effect into a detectable pattern by analyzing dark current variations. By treating the noise-induced pixel value changes as informative data rather than mere interference, the system identifies and corrects affected pixels, transforming the noise problem into a solvable detection and correction task that preserves image quality
2Area of stationary object
If miniaturization of pixel and read-out circuit is implemented, then area is reduced, but noise increases and sensitivity decreases
Solution Approach 1:
The system performs preliminary detection of RTS noise characteristics by capturing multiple dark images before actual imaging. This advance detection allows the system to build a noise profile for each pixel, enabling targeted correction that compensates for the increased noise inherent in miniaturized circuits while maintaining the area benefits
3Speed
If simple RTS noise correction is applied, then correction speed is improved, but accuracy decreases due to fixed correction amounts
Solution Approach 1:
The patent transitions from static, fixed correction amounts to dynamic, adaptive correction values. By calculating correction amounts based on actual pixel characteristics and observed noise patterns from dark images, the system adjusts correction strength individually for each affected pixel, achieving both efficiency and accuracy in noise correction
Solution Approach 2:
The system changes the correction parameter from a fixed value to a variable determined by pixel-specific noise characteristics. By analyzing the distribution of pixel values in dark images and identifying RTS noise patterns, the system derives adaptive correction parameters that optimize both correction speed and accuracy for each pixel
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively corrects RTS noise, improving image quality by accurately determining and mitigating the noise impact on pixel values, enhancing sensitivity and reducing noise levels in image data.
Implementation Method 1
a plurality of pixels arranged two-dimensionally to receive light from outside and generate a signal corresponding to an amount of the received light
Data Source
AI summary
Provided is an image processing apparatus for correcting blinking defect noise included in image data generated by an image sensor, the image sensor including pixels arranged two-dimensionally and read-out circuits configured to read out a pixel value. The image processing apparatus is configured to: acquire noise information that associates the pixel value with positional information of the read-out circuits or positional information of each of the pixels, and with feature data related to blinking defect noise attributed to the read-out circuits; determine whether the blinking defect noise occurs on a pixel of interest based on the noise information; calculate candidate values indicating a correction amount for correcting the blinking defect noise based on the noise information and a pixel value of the pixel of interest if the blinking defect noise occurs; and correct the pixel value of the pixel of interest based on the candidate values.