Wide-Angle Thermal Imager Position Correction for Occupancy Tracking
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Solution Overview
Problem
Existing thermal imagers with wide-angle lenses for building management suffer from visual distortions, making it difficult to precisely determine the position of individuals in a space, which complicates energy management, occupancy tracking, and fire protection device placement.
Innovation Solution
A method using a thermal imager with a wide-angle lens that applies a wide-angle correction function to compensate for distortion by determining the polar coordinates of a region of interest and applying a normalization and metric factor to correct the distance, along with an optional angular correction, to accurately locate individuals in a space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a wide-angle lens is used to capture a larger area of space, then the field of view is increased, but visual distortions appear making precise position determination difficult
Solution Approach 1:
The patent applies a distortion correction function to the thermal image before processing it to determine person positions. This preliminary correction action compensates for the wide-angle lens distortion, transforming the distorted image into a geometrically accurate representation that enables precise position determination while maintaining the wide field of view
Solution Approach 2:
The patent transforms the distorted thermal image coordinates into corrected coordinates using a distortion correction function that adjusts spatial parameters. By changing the coordinate system parameters to account for lens distortion, the system recovers accurate position information from the wide-angle captured image
2Measurement precision
If distortion correction is applied to the entire thermal image, then position accuracy is improved, but computational load increases
Solution Approach 1:
The patent extracts only the region of interest (person detection zones) from the distorted thermal image and applies distortion correction specifically to these extracted regions. This selective approach maintains position accuracy for detected persons while significantly reducing the computational load compared to correcting the entire image
Solution Approach 2:
The patent applies distortion correction partially - only to the extent necessary for person position determination. By focusing correction efforts on relevant regions rather than the complete image, the system achieves sufficient position accuracy with reduced computational resources
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
Enables precise positioning of individuals in a space with reduced computational load, enhancing energy management, occupancy tracking, and fire protection device placement accuracy while avoiding overcounting.
Implementation Method 1
capable of capturing the infrared radiation emitted by bodies present in the space and creating thermal images of the space from this captured radiation
Data Source
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AI summary
Method for obtaining the position of a person in a space (E) of a building by a thermal imager (10) comprising a wide-angle lens, the method comprising: a) acquisition by the thermal imager through its wide-angle lens of a distorted thermal image of a scene (S) including the person (P), the distorted thermal image including a hot area corresponding to the person present in the scene (S); b) extraction of a region of interest corresponding to the person from the distorted thermal image using an algorithm; c) determination of the position of the region of interest by identifying the polar coordinates distance r and angle θ of the center of the region of interest in a polar coordinate system whose origin is at the center of the distorted thermal image; d) obtaining the actual position of the person by applying a wide-angle correction function to the distance r.