Camera Orientation Using Photogrammetric Scene Reconstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the absolute yaw orientation of a camera in optical see-through systems are unreliable, noisy, or require bulky infrastructure, making them unsuitable for many applications.
Innovation Solution
A method involving an image capturing device placed in at least three grid positions to reconstruct a scale model of a scene, using point, line, and region correspondences to determine a similarity transform from a photogrammetric coordinate system to a global coordinate system, allowing for the determination of rotation, translation, and scale transformations to achieve absolute orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional references (solar, astral, magnetic field, radio beacons) are used to determine yaw, then orientation information can be obtained, but the system becomes unreliable, noisy, or requires bulky infrastructure
Solution Approach 1:
The patent creates a photogrammetric model (a copy representation) of the scene containing multiple objects with known spatial relationships. Instead of relying on external physical references like radio beacons or magnetic field sources, the system uses a reconstructed 3D model of the environment itself as the reference framework for determining camera orientation.
Solution Approach 2:
The system determines yaw orientation using only the image capturing device and processed images of the scene. The photogrammetric model is built from images captured by the same device, making the system self-contained without requiring external infrastructure like radio beacons, magnetic field sources, or other bulky reference systems.
2Measurement precision
If photogrammetric reconstruction is performed using multiple views from grid positions, then absolute orientation can be determined, but the process requires multiple positioning measurements and coordinate transformations
Solution Approach 1:
The patent introduces a photogrammetric coordinate system as an intermediary reference framework. Images captured from multiple known grid positions are used to construct a 3D model in this intermediate coordinate system, which then serves as the basis for determining the camera's absolute orientation through similarity transformation to the global coordinate system.
Solution Approach 2:
The orientation determination process is divided into distinct segments: (1) capturing images at multiple predetermined grid positions with known coordinates, (2) performing photogrammetric reconstruction to create a 3D model in photogrammetric coordinates, and (3) applying similarity transformation to convert to global coordinates and extract absolute orientation. This segmentation makes the complex process more manageable and systematic.
Data Source
AI summary
A method for determining an absolute orientation in a global coordinate system is provided. In each grid position an image capturing device is directed to a selected object located in a scene. The method comprises: (A) reconstructing a scale model of the scene using point, line and/or region correspondences in multiple views of the scene obtained by the image capturing device placed in at least three grid positions; (B) obtaining location coordinates of at least three grid positions in the global coordinate system; and (C) determining a similarity transform from a photogrammetric coordinate system to the global coordinate system by determining rotation, translation and scale of the image capturing device for each grid position.