Camera Parameter Set Calculation Using Mutual Image Observation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camera calibration techniques require reference points with known three-dimensional coordinate sets, necessitating special equipment like calibration markers or measurement devices, which is impractical for many applications.
Innovation Solution
A method and apparatus that calculate camera parameter sets without pre-defined three-dimensional coordinate sets by using a second camera as a reference to update the camera parameter set based on pixel values from both cameras capturing the same subject, allowing calibration without the need for specific reference points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional camera calibration techniques are used requiring reference points with known three-dimensional coordinate sets, then measurement precision can be maintained, but device complexity and ease of operation deteriorate due to requiring calibration markers or three-dimensional measurement devices
Solution Approach 1:
The system uses the cameras themselves to perform calibration by capturing images of each other. The first camera captures an image of the second camera, and the second camera captures an image of the first camera. This self-calibration approach eliminates the need for external calibration markers or measurement devices, allowing the system to calibrate itself while maintaining measurement precision through mutual observation and coordinate transformation.
Solution Approach 2:
The patent introduces an intermediary coordinate transformation process that maps points between the two camera coordinate systems. By establishing correspondence relationships between points captured by each camera and transforming coordinates through mathematical relationships, the system achieves calibration without direct physical reference objects, using the cameras as intermediaries to establish spatial relationships.
2Measurement precision
If calibration markers or three-dimensional measurement devices are used, then camera parameter set calculation accuracy is improved, but ease of operation worsens due to the need for special equipment preparation
Solution Approach 1:
The calibration process is simplified by eliminating the need for operators to prepare or position external calibration markers. The cameras automatically capture images of each other, and the control device performs the calibration calculations based on these mutual images. This self-service approach makes the calibration process as simple as capturing images, removing the operational burden of setting up special equipment.
Solution Approach 2:
Instead of using external devices to measure and input camera parameters, the patent inverts the approach by having the cameras measure each other. The first camera observes the second camera and vice versa, allowing the system to derive calibration parameters from the reciprocal imaging relationship rather than from external measurement tools.
3Ease of operation
If mutual image capture between two cameras is performed for calibration, then ease of operation is improved by eliminating calibration markers, but measurement precision must be maintained through accurate coordinate transformation
Solution Approach 1:
The patent establishes an intermediary coordinate transformation system that acts as a mathematical bridge between the two camera coordinate systems. By defining transformation relationships that map points from one camera's coordinate system to the other's, the system maintains measurement precision through rigorous mathematical relationships while keeping the operational process simple.
Solution Approach 2:
The calibration process incorporates feedback mechanisms where the captured images and calculated parameters are used to refine the coordinate transformation relationships. The system iteratively improves the transformation accuracy by using the actual captured image data to adjust and optimize the mathematical models, ensuring measurement precision is maintained throughout the calibration process.
Data Source
AI summary
A camera parameter set calculation apparatus calculates three-dimensional coordinate sets based on a first image obtained by a first camera mounted on a mobile apparatus, a second image obtained by a second camera arranged on or in an object different from the mobile apparatus, a camera parameter set of the first camera, and a camera parameter set of the second camera, determines first pixel coordinate pairs obtained by projecting the three-dimensional coordinate sets onto the first image based on the first camera parameter set and second pixel coordinate pairs obtained by projecting the three-dimensional coordinate sets onto the second image based on the second camera parameter set, calculates an evaluation value based on pixel values at the first pixel coordinate pairs and pixel values at the second pixel coordinate pairs, and updates the camera parameter set of the first camera based on the evaluation value.