Defective Pixel Detection via Spatial-Temporal Gradient Analysis

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Solution Overview

Problem

Existing techniques for detecting defective pixels in video content are labor-intensive, time-consuming, and prone to errors, leading to a degraded viewing experience due to visual anomalies.

Innovation Solution

The implementation of a distributed execution framework that uses high-level statistics-based spatial filtering and temporal consistency filtering to automatically detect defective pixels in video content, reducing manual effort and increasing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual detection of defective pixels is performed by quality control personnel viewing video content multiple times, then detection capability is achieved, but time consumption and labor intensity increase significantly

Engineering Contradiction:
Improvedefective pixel detection capabilityVSAvoidtime consumption for detection
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the manual mechanical inspection process with an automated computer-based system that uses image processing algorithms to detect defective pixels. The system automatically analyzes video frames, identifies defective pixel patterns, and generates detection results without requiring human operators to manually view and analyze each frame, thereby eliminating the time-consuming manual inspection process while maintaining detection capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The detection system performs self-analysis by automatically processing video content through computational algorithms. The system independently identifies defective pixels by comparing pixel values across multiple frames, detecting anomalies without human intervention, and generating detection reports autonomously, thus eliminating the need for continuous manual monitoring and significantly reducing detection time.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If manual inspection of video content is performed to detect defective pixels, then detection is possible, but error rate increases due to human oversight

Engineering Contradiction:
Improvedefective pixel detection capabilityVSAvoiddetection accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces human manual inspection with an automated computational system that uses consistent algorithms to analyze video content. This substitution eliminates human factors such as fatigue, distraction, and variability in attention that lead to errors. The automated system applies the same detection criteria uniformly across all video content, ensuring consistent and reliable detection results without the variability inherent in manual inspection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system incorporates feedback mechanisms where detection results are continuously refined through algorithmic analysis. The system compares detected anomalies against established patterns of defective pixels, validates findings through multiple analysis passes, and adjusts detection parameters based on accumulated data, thereby improving reliability and reducing error rates through iterative self-correction rather than relying on human judgment.

Inventive Principle:
Principle #23Feedback

3Extent of automation

If conventional quality control tools are used to detect defective pixels, then automation is partially achieved, but false positive rate increases requiring manual intervention

Engineering Contradiction:
Improveautomation level in detectionVSAvoiddetection accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent applies localized analysis by examining specific spatial regions and temporal sequences independently. Instead of applying uniform detection thresholds across the entire video content, the system adapts its analysis to local characteristics of different video segments, adjusting detection parameters based on scene complexity, motion patterns, and spatial distribution of pixels. This localized approach reduces false positives by distinguishing between genuine defective pixel patterns and normal variations in different video regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system employs dynamic detection thresholds and adaptive analysis parameters that change based on the characteristics of the video content being analyzed. Rather than using static, fixed criteria, the system adjusts its sensitivity and detection parameters in real-time based on scene complexity, motion intensity, and spatial-temporal patterns, thereby maintaining high detection accuracy while reducing false positives across diverse video content without requiring manual intervention.

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If multiple viewings of video content are performed to ensure thorough detection, then detection completeness improves, but productivity decreases

Engineering Contradiction:
Improvedetection completenessVSAvoiddetection throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuous automated processing that analyzes video content in a single uninterrupted pass rather than requiring multiple discrete viewings. The system processes video frames continuously through its detection algorithms, maintaining constant analysis throughput while ensuring thorough examination of all pixels. This continuous automated action achieves detection completeness equivalent to multiple manual viewings but maintains high productivity by eliminating the need to restart analysis for each viewing cycle.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system performs preliminary analysis by pre-processing video content and identifying potential defective pixel candidates before final detection. It conducts initial scanning to flag suspicious patterns, then applies more intensive analysis only to those specific regions, rather than uniformly analyzing all pixels multiple times. This preliminary action approach ensures detection completeness by thoroughly examining all potential defects while maintaining productivity by avoiding redundant full-content analysis.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3698317B1Techniques for detecting spatial anomalies in video content
Publication Date: 2025.05.21 NETFLIX INC
  • EP3698317B1 patent drawingFigure 1
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AI summary

In various embodiments, a defective pixel detection application automatically detects defective pixels in video content. In operation, the defective pixel detection application computes a first set of pixel intensity gradients based on a first frame of video content and a first neighborhood of pixels associated with a first pixel. The defective pixel detection application also computes a second set of pixel intensity gradients based on the first frame and a second neighborhood of pixels associated with the first pixel. Subsequently, the defective pixel detection application computes a statistical distance between the first set of pixel intensity gradients and the second set of pixel intensity gradients. The defective pixel detection application then determines that the first pixel is defective based on the statistical distance.