Emergency Vehicle Light Detection Using Color and Flash Frequency

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Solution Overview

Problem

Existing ADAS systems struggle to reliably distinguish emergency vehicles from standard vehicles due to variability in vehicle types, lighting conditions, and occlusions, leading to inaccurate detection and potential obstruction of emergency vehicle passages.

Innovation Solution

An image processing method using colorimetric segmentation, tracking, and frequency analysis to detect emergency vehicles by identifying flashing lights, incorporating post-segmentation filtering and classification to reduce false positives, and calculating an overall confidence index for reliable detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing ADAS systems use standard vehicle detection methods, then all vehicles can be detected, but priority vehicles cannot be reliably distinguished from standard vehicles

Engineering Contradiction:
Improvedetection accuracyVSAvoidvehicle type differentiation
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies colorimetric segmentation to detect the characteristic flashing colors of emergency vehicle lights. The system segments images based on color information to identify red, yellow, blue and other colored flashing lights that distinguish priority vehicles from standard vehicles, resolving the contradiction between general detection and specific differentiation.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent utilizes frequency analysis to detect the periodic flashing pattern of emergency lights. By analyzing the temporal frequency of light intensity variations, the system can reliably identify priority vehicles with flashing beacons, solving the problem of distinguishing vehicle types while maintaining broad detection capability.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the system detects all luminous areas, then flashing lights can be identified, but false positives from other lights increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoidfalse positives
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes detection parameters by combining colorimetric segmentation with frequency analysis. Instead of detecting all luminous areas, the system specifically identifies lights that exhibit both characteristic colors and periodic flashing patterns, significantly reducing false positives from stationary lights or non-flashing sources while maintaining high reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system employs a confidence index calculation that integrates multiple detection criteria (color segmentation results, frequency analysis outcomes, and tracking consistency). This feedback mechanism allows the system to filter detections and reduce false positives by requiring multiple criteria to be satisfied simultaneously.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the system uses multiple detection criteria, then detection accuracy improves, but processing time increases

Engineering Contradiction:
Improvedetection precisionVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary colorimetric segmentation to pre-identify candidate luminous areas before performing more computationally intensive frequency analysis. This preliminary filtering reduces the number of candidates requiring full multi-criteria evaluation, thereby maintaining high detection precision while reducing overall processing time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The detection process is segmented into distinct stages: colorimetric segmentation to identify candidate areas, frequency analysis to verify flashing patterns, and confidence index calculation to confirm detections. This segmentation allows the system to apply different processing levels to different candidates, optimizing the balance between precision and processing time.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4229544B1Method for processing images to declare a segmented area as revolving light
Publication Date: 2025.12.24 AUMOVIO AUTONOMOUS MOBILITY GERMANY GMBH
  • EP4229544B1 patent drawingFigure 1
  • EP4229544B1 patent drawingFigure 2
  • EP4229544B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for processing a video stream of images captured by a colour camera (2) and used by a computer (3) on board a motor vehicle (1) in order to detect a priority vehicle (4), the method comprising the following steps: - a step (100) of acquiring an image sequence; for each image of the image sequence: - a step (200) of colour segmentation by thresholding allowing the detection of coloured light areas; - a step (300) of tracking each segmented light area; - a step (400) of colour classification of each segmented light area; - a step (500) of frequency analysis of each segmented light area allowing a flashing nature of the area to be determined; - a step (700) of calculating an overall reliability index of each image of the sequence of images, allowing a light area to be identified as a rotating light.