Analog Opaque Pixel Voting for Row Noise Suppression
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Solution Overview
Problem
Conventional methods for reducing row noise in digital imaging, such as adding opaque columns, are inadequate as they can introduce additional noise, consume power, and are compromised by dead, hot, or blinking pixels, leading to aesthetically unpleasing stripes and potential rejection in quality control.
Innovation Solution
A system and method that includes a pixel array with both imaging and opaque pixels, utilizing an analog voting component with operational transconductance amplifiers (OTAs) to suppress outliers and perform opaque subtraction in the analog domain, followed by analog-to-digital conversion to reduce row noise effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If opaque columns are added to the FPA to reduce row noise, then row noise is reduced, but dead, hot, or blinking pixels in the opaque columns introduce stripes and reduce reliability
Solution Approach 1:
The patent extracts and removes outlier pixel values (dead, hot, blinking pixels) from the opaque column data before using it for row noise reduction. This is achieved through statistical outlier detection and removal algorithms that identify and exclude problematic pixel readings, allowing the opaque column subtraction method to proceed without introducing stripes or artifacts into the final image.
Solution Approach 2:
The patent introduces an intermediary processing step between opaque column acquisition and row noise subtraction. This intermediary layer performs quality control, outlier detection, and data validation on the opaque pixel readings, ensuring that only reliable data is used for noise reduction. This mediator prevents defective pixel data from propagating into the final image as visible stripes.
2Reliability
If ADC is used to mitigate stripes from opaque pixel defects, then stripe artifacts are reduced, but power consumption increases and dynamic range is reduced
Solution Approach 1:
The patent replaces the ADC-based stripe mitigation approach with an analog signal processing method. Instead of converting to digital and processing, the solution uses analog voting circuits and statistical processing in the analog domain to identify and suppress outlier signals from defective opaque pixels. This substitution eliminates the need for high-power ADC operation while achieving the same stripe reduction goal.
Solution Approach 2:
The patent performs outlier suppression and data validation on opaque pixel readings before they are used for row noise subtraction. By pre-processing the opaque column data to remove defective pixel values beforehand, the system prevents stripe artifacts from being introduced in the first place, eliminating the need for subsequent ADC-based correction and reducing overall power consumption.
3Object-affected harmful factors
If opaque pixel data is used for row noise reduction, then row noise is reduced, but dead, hot, or blinking opaque pixels create stripes across the image
Solution Approach 1:
The patent extracts and removes outlier pixel values (dead, hot, blinking pixels) from the opaque column data before using it for row noise reduction. This is achieved through statistical outlier detection and removal algorithms that identify and exclude problematic pixel readings, allowing the opaque column subtraction method to proceed without introducing stripes or artifacts into the final image.
Solution Approach 2:
The patent implements a feedback mechanism where the system continuously monitors opaque pixel readings for outliers and adjusts the noise reduction process accordingly. When defective pixels are detected in the opaque columns, the system automatically compensates by using alternative data sources or adjusting subtraction weights, preventing stripe artifacts from appearing in the final image while maintaining effective row noise reduction.
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
This approach significantly reduces row noise while minimizing the impact of outliers like dead or hot pixels, enhancing image quality without the drawbacks of traditional methods, such as power consumption and noise introduction, making the imaging system more commercially viable.
Implementation Method 1
analog voting component with operational transconductance amplifiers (OTAs) to suppress outliers and perform opaque subtraction in the analog domain
Implementation Method 2
analog voting component is operatively connected to the sub-array of opaque pixels to receive analog image data from the sub-array of opaque pixels
Implementation Method 3
The filtering component is operatively connected to the analog voting component for subtracting row averages from the sub-array of opaque pixels to reduce row noise in analog image data from the sub-array of imaging pixels
Implementation Method 4
An analog to digital conversion (ADC) component can be operatively connected to receive analog image data from the filtering component for conversion into digital image data
Data Source
AI summary
A method including collecting analog image data from an imaging array wherein the analog image data includes analog image data from a plurality of imaging pixels and from a plurality of opaque pixels. Each row of the imaging array includes both imaging pixels and opaque pixels. Opaque subtraction is performed in an analog domain, wherein biases determined in the opaque pixels for a given row of the imaging array are subtracted from the analog image data of the imaging pixels of that given row for each row of the imaging array. Performing opaque subtraction includes suppressing outliers in the analog image data from the plurality of opaque pixels. The method includes performing analog to digital conversion (ADC) on the analog image data to produce digital image data for the imaging pixels. ADC is performed after opaque subtraction in the analog domain.