HMD AR Alignment via Marker Calibration
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Solution Overview
Problem
Existing head-mounted display devices face challenges in accurately superimposing augmented reality images onto specific objects due to variations in camera parameters and the relative positional relationship between the camera and image display sections, leading to inaccuracies in spatial alignment.
Innovation Solution
A head-mounted display device and accompanying program that optimize camera parameters by overlaying a marker image with an actual object marker, using a calibration process to derive precise spatial and camera parameters, ensuring accurate alignment of AR images with real objects through image processing and optimization techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a camera is used to capture real objects and AR images are superimposed on them, then the AR function convenience is improved, but the spatial alignment accuracy deteriorates due to variations in camera parameters and relative positional relationships
Solution Approach 1:
The patent applies parameter changes by performing calibration to determine accurate camera parameters (focal length, principal point) and relative positional parameters between the camera and image display sections. This process adjusts and optimizes these parameters to compensate for manufacturing variations, thereby resolving the contradiction between operational convenience and measurement precision.
2Ease of manufacture
If manufacturing accuracy is relaxed to reduce costs, then the ease of manufacture is improved, but the camera parameters and relative positional relationships vary, causing alignment errors
Solution Approach 1:
The patent applies preliminary action by performing calibration before actual AR operations. The calibration process pre-determines the camera parameters and relative positional parameters, storing them for use during AR operations. This preliminary calibration step compensates for manufacturing variations without requiring high manufacturing precision, thus resolving the contradiction between ease of manufacture and manufacturing precision.
3Measurement precision
If the number of calibration points is increased to improve calibration accuracy, then the measurement precision is improved, but the calibration time and complexity increase
Solution Approach 1:
The patent applies self-service by enabling the system to automatically capture images of multiple calibration points and compute camera parameters and relative positional parameters without requiring manual intervention for each point. The automated image processing and parameter computation reduce calibration time while maintaining high accuracy through the use of multiple calibration points.
Data Source
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AI summary
A head-mounted display device includes an image display section configured to display an image, a camera, a memory section configured to store data of a marker image, an image setting section configured to cause the image display section to display an image based at least on the data, and a parameter setting section. The parameter setting section derives at least one of camera parameters of the camera and a spatial relationship, the spatial relationship being between the camera and the image display section, based at least on an image that is captured by the camera in the case where the camera acquires a captured image of a real marker.