Projection System Calibration Using Stored Reference Data
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Solution Overview
Problem
Current multi-projector systems lack the ability to automatically recalibrate after changes, requiring a full recalibration process upon any projector change, which is time-consuming and often results in inaccuracies due to limited camera views and hardware restrictions.
Innovation Solution
A method for automatic restoration of the measured state using a combination of incomplete new measurement data with denser initial measurement data, employing multivariate interpolation and error weighting to improve calibration accuracy across the projection surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full recalibration process is performed after any projector change, then the projection system can be realigned to its original state, but the process becomes time-consuming and results in inaccuracies due to limited camera views and hardware restrictions
Solution Approach 1:
The patent applies partial action by performing only a partial recalibration process instead of a full recalibration. The system identifies that only certain projection channels may have changed and recalibrates only those specific channels using stored reference data from the original calibration, rather than recalibrating the entire system. This reduces both time and potential sources of error while maintaining overall system accuracy.
Solution Approach 2:
The patent implements preliminary action by storing reference calibration data during the initial calibration phase. This reference data includes information about the original projection geometry and overlap characteristics. When a projector changes or recalibration is needed, this pre-stored reference data is used to guide the recalibration process, eliminating the need to perform a complete recalibration from scratch and significantly reducing recalibration time.
2Ease of operation
If camera-based systems are used to reduce setup effort, then the alignment process becomes faster, but the systems require high conditions such as complete view of the projection surface which is often not achievable
Solution Approach 1:
The patent uses stored reference calibration data as an intermediary element that mediates between the limited camera view and the need for accurate recalibration. Instead of relying solely on real-time camera observations which may be incomplete, the system combines available camera data with pre-stored reference information about the original projection geometry. This intermediary reference data compensates for the camera's limited view and ensures reliable recalibration results even when the projection surface cannot be completely viewed.
3Reliability
If the entire recalibration procedure is repeated upon projector change, then the system can be realigned, but the complexity and time required increase significantly
Solution Approach 1:
The patent extracts and separates the essential calibration information into stored reference data that can be reused. Instead of repeating the entire complex recalibration procedure, the system extracts only the necessary reference geometric parameters from the original calibration and stores them for future use. When recalibration is needed, only the minimal necessary measurements are taken and combined with the extracted reference data, significantly reducing procedural complexity while maintaining alignment accuracy.
Data Source
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AI summary
The invention, which relates to a method for automatically restoring a calibrated state of a projection system, is based on the object of specifying a solution that allows simple and error-free alignment of a projection system in an original error-free state of the projection system. This object is achieved in that a calibrated state of a projection system is automatically restored by calculating or checking a position and orientation of the one or more cameras within the projection system, wherein fixed points are used, in that subsequently m times n markers (9') are projected onto the projection area, said markers being used by one or more cameras to determine a reduced number, in comparison with the calibration, of second measurement points (Ql ') that have one X, Y and Z coordinate each, in that the reduced number of second measurement points (Ql ') is used to perform a calculation of the differences between the second measurement points (Ql ') and the associated first measurement points (Ql '), and a displacement vector is formed, in that the association between the projector coordinates and 3D coordinates is adapted by means of the displacement vector.