Camera Contrast Detection Using CSNR for Real-Time Assessment

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Solution Overview

Problem

Existing methods for evaluating the contrast detection capabilities of imaging systems, such as cameras, are either too time-consuming and resource-intensive (like SNRI) or limited in accuracy and applicability (like CDP), making them unsuitable for real-time or field-based assessments, especially for machine vision tasks like autonomous driving.

Innovation Solution

The introduction of the contrast signal-to-noise ratio (CSNR) metric, which is proportional to SNRI, simple to calculate, and non-saturating, allowing for real-time evaluation of camera performance across various lighting conditions, enabling automatic adjustment of camera parameters for improved functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If SNRI (signal-to-noise ratio idealized) is used to evaluate camera contrast detection capabilities, then measurement accuracy is improved, but measurement time and computational complexity increase significantly

Engineering Contradiction:
Improvecontrast detection measurement accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the essential measurement functionality from the complex SNRI calculation by identifying and measuring only the critical components needed for contrast detection capability assessment. Instead of performing the full SNRI calculation, the system extracts and measures contrast detection probability (CDP) and contrast signal-to-noise ratio (CSNR) as simplified surrogate metrics that capture the essential measurement intent without the computational overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates simplified proxy measurements (CDP and CSNR) that replicate the essential information obtained from full SNRI measurements. These proxy metrics serve as lightweight copies that provide sufficient measurement accuracy for practical applications while requiring minimal computational resources and time.

Inventive Principle:
Principle #26Copying

2Measurement precision

If traditional contrast detection measurement methods are used, then measurement accuracy is maintained, but device complexity and resource requirements increase

Engineering Contradiction:
Improvecontrast detection capability measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs simple, easily computable metrics (CDP and CSNR) that can be calculated rapidly from standard camera output data. These metrics serve as disposable, lightweight measurement tools that provide sufficient accuracy for practical purposes without requiring complex measurement systems or extensive computational resources.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If comprehensive contrast detection measurements are performed in laboratory conditions, then measurement accuracy is improved, but adaptability to real-world field conditions decreases

Engineering Contradiction:
Improvecontrast detectability measurement accuracyVSAvoidapplicability to field conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent develops measurement metrics (CDP and CSNR) that are universally applicable across different camera systems and operating conditions. These metrics can be calculated from standard camera output data regardless of whether the camera is operating in controlled laboratory environments or varied field conditions, making the measurement system highly adaptable and versatile.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The measurement system uses the camera's own output data to perform self-assessment of its contrast detection capabilities. By analyzing the camera's captured images and computing CDP/CSNR from the actual output, the system enables real-world field cameras to automatically evaluate their own performance without requiring external measurement equipment or controlled laboratory conditions.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11652982B2Applications for detection capabilities of cameras
Publication Date: 2023.05.16 NVIDIA CORP
  • US11652982B2 patent drawing
  • US11652982B2 patent drawing
  • US11652982B2 patent drawing

AI summary

In one embodiment, a system receives pixel data from a pair of regions of an image generated by an imaging device, the pair of regions includes a first region and a second region, where the first region includes a first plurality of pixels and the second region includes a second plurality of pixels. The system determines a plurality of pixel pairs, where a pixel pair includes a first pixel from the first plurality of pixels and a second pixel from the second plurality of pixels. The system calculates a plurality of contrasts based on the plurality of pixel pairs. The system determines a contrast distribution based on the plurality of contrasts. The system calculates a value representative of a capability of the imaging device to detect contrast based on the contrast distribution. The system determines a reduction in contrast detectability of the imaging device based on the value.