Emergency Vehicle Detection via Color Ratio Frequency Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting emergency vehicles using image analysis are computationally intensive and require complex processes, including identification of specific light sources and matching with templates, which can be inefficient and fail when light sources are occluded or reflected.
Innovation Solution
A method that calculates the EV colour component for pixels in image frames, generates a time domain representation, and converts it to a frequency spectrum to identify flashing light sources without requiring specific light source identification or matching, allowing detection of emergency vehicles based on visible and reflected light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex light source identification and template matching methods are used, then detection accuracy may be improved, but computational demand and processing time increase significantly
Solution Approach 1:
The patent extracts only the essential color information (EV color component) from image pixels, ignoring other complex features like light source shape, position, and pattern. This extraction of the critical color feature enables efficient processing while maintaining detection accuracy, as emergency vehicle lights have distinctive color signatures that can be identified through simple ratio calculations of color channels.
Solution Approach 2:
The patent transforms the detection approach by changing from analyzing multiple parameters (light source geometry, position, temporal patterns) to focusing on a single transformed parameter - the EV color component ratio. This parameter transformation simplifies the detection process and reduces computational complexity while preserving the ability to distinguish emergency vehicle lights from other light sources.
2Reliability
If specific light source identification is required, then detection reliability may be improved, but the system fails when light sources are occluded or reflected
Solution Approach 1:
The patent creates a universal detection method that works for all emergency vehicle light sources regardless of their specific characteristics. By detecting the EV color component ratio rather than identifying specific light source types or patterns, the system becomes adaptable to various scenarios including occluded lights, reflected lights, and different emergency vehicle configurations, maintaining reliability across diverse conditions.
Solution Approach 2:
The patent changes the detection parameter from light source identification (which requires recognizing specific patterns and shapes) to color ratio analysis (which detects the inherent spectral signature). This parameter change makes the detection robust to occlusions and reflections, as the color signature persists even when the physical light source is partially blocked or reflected off surfaces.
3Measurement precision
If template matching and light source identification processes are implemented, then detection precision may be improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent extracts only the necessary color information from each pixel, discarding unnecessary data about light source geometry, position, and temporal patterns. This selective extraction of the critical EV color component simplifies the processing algorithm while maintaining detection precision, as the color ratio contains sufficient information to distinguish emergency vehicle lights from other sources.
Solution Approach 2:
The patent replaces complex mechanical/image processing operations (template matching, light source localization, pattern recognition) with a simple mathematical calculation of color channel ratios. This substitution of complex processing with a straightforward computational operation reduces device complexity and processing requirements while preserving detection accuracy.
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A method for detecting the presence of an emergency vehicle is provided. The method comprises receiving a plurality of image frames taken by an image sensor over a period of time, determining an EV colour component for a plurality of pixels in each image frame based on the ratio of a first colour relative to the total colour in each pixel and assigning to a pixel a first value if the EV colour component exceeds a predefined threshold value and a second value if the EV colour component does not, and determining for each of the plurality of image frames an EV colour value for the first colour based on the sum of all of the first values for each image frame. The method also comprises generating a time domain representation based on the EV colour values associated with the plurality of image frames, converting the time domain representation for the plurality of image frames to a frequency spectrum, and determining if any flashing light sources of the first colour associated with one or more types of emergency vehicles is present by analysing the frequency spectrum.