Calibrating Laser Scanner and Camera Using Intensity Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for calibrating measuring systems with a laser scanner and image capture device require the creation of remission images, which are not always available or of sufficient quality, limiting their precision and applicability to specific systems.
Innovation Solution
A method that prepares images and 3D point clouds from different viewpoints, identifies homologous points, and uses an optimization sequence to determine calibration parameters without relying on remission images, allowing for precise calibration of the image capture device and laser scanner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If remission images are used for calibration, then calibration precision is improved, but the method is limited to specific laser scanner systems and remission images are not always available or of sufficient quality
Solution Approach 1:
The patent extracts the calibration process from dependency on remission images by using only the intensity information already present in standard images captured by the image capture device. This eliminates the need for specialized remission images while maintaining calibration capability across different system configurations.
Solution Approach 2:
The calibration method is designed to be universally applicable to various laser scanner and image capture device configurations without requiring system-specific remission images. The same calibration approach works across different spectral regions and device types by utilizing the universally available intensity information in standard images.
2Measurement precision
If remission images with high spatial resolution are created, then calibration precision is improved, but the complexity of the calibration process increases
Solution Approach 1:
The patent removes the complex step of creating and processing remission images by directly using intensity information from standard captured images. This simplification maintains calibration precision while eliminating the need for specialized image processing pipelines.
Solution Approach 2:
Instead of creating specialized remission images through complex processes, the method uses the existing intensity information in standard images as a proxy, effectively copying the useful calibration data from readily available sources without requiring additional specialized capture or processing steps.
3Adaptability or versatility
If intensity information from laser scanner is used, then calibration can be performed without remission images, but the intensity information is not always available or of sufficient quality
Solution Approach 1:
The patent introduces the intensity information from standard images as an intermediary that bridges the gap between the laser scanner data and calibration requirements. This intermediary provides the necessary intensity correlation without requiring direct access to laser scanner intensity outputs or specialized remission images.
Solution Approach 2:
The method copies intensity information from the image capture device's standard images, which are universally available across different systems. This copying approach ensures calibration can proceed without relying on system-specific intensity data availability while maintaining sufficient quality for accurate calibration.
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
This method enables precise calibration of the measuring system, ensuring that 3D points from different images align closely, facilitating the fusion of 2D image data with 3D point clouds, and is applicable to a wide variety of laser scanners.
Implementation Method 1
The distance between the optical emission center of the scanner and the point of reflection on the illuminated object is determined from the flight time, i.e., the time between the emission of the beam and the reception of the reflected beam
Implementation Method 2
The laser scanner is sometimes provided with means that allow the beam to be oriented in a specific direction, for example, a rotating mirror, the movement of which makes it possible to scan a part of the scene with the beam
Data Source
AI summary
A method for calibrating a measuring system, the system comprising an image capture device, a laser scanner, and a positioning unit, wherein the method comprises preparing at least two images supplied by the image capture device and preparing a 3D point cloud; identifying at least one homologous point in the images and performing an optimization sequence for determining at least one calibration parameter of the measuring system. The sequence comprises at least one iteration of the following steps: for each image, identifying, in the 3D point cloud, at least one close point projecting in a neighborhood of the homologous point of the image; performing a measurement of the distance separating the close points respectively associated with the images; and adjusting the calibration parameter according to the measurement performed.