Camera Calibration Using Single Rectangular Image
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current camera calibration methods are cumbersome and not suitable for real-time applications, particularly for inexpensive cameras like smartphone cameras, as they require complex three-dimensional objects or multiple images of a checkerboard, which are not easily available in normal environments.
Innovation Solution
A method for camera calibration using a single rectangular image with an arbitrary size and aspect ratio, which recovers geometric information to determine the camera's intrinsic and extrinsic parameters, allowing for the detection of the shooting position and real geometric information through the generation of a centered quadrangle and two-dimensional segment camera models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single image with arbitrary rectangular size is used for calibration, then the ease of operation and accessibility are improved, but the measurement precision and reliability deteriorate
Solution Approach 1:
The patent transforms the calibration problem by changing the parameter representation from direct coordinate measurement to projective geometric relationships. By using homography matrices and projective transformation parameters, the system can accurately calibrate cameras using arbitrary rectangular images without requiring precise physical measurements, thus maintaining high measurement precision while improving ease of operation.
Solution Approach 2:
The patent introduces an intermediary mathematical model (projective geometry and homography) that bridges the gap between simple rectangular images and accurate camera calibration. This intermediary framework allows the system to extract precise extrinsic parameters from easily obtainable rectangular images, resolving the contradiction between ease of use and calibration accuracy.
2Measurement precision
If complex three-dimensional calibration objects are used, then the measurement precision is improved, but the device complexity and ease of manufacture worsen
Solution Approach 1:
The patent extracts only the essential geometric features needed for calibration from complex three-dimensional objects, reducing the calibration target to a simple rectangular image. By taking out only the necessary projective geometric information and discarding unnecessary complexity, the system achieves accurate calibration while dramatically simplifying the calibration object.
Solution Approach 2:
The patent replaces expensive, complex, and durable calibration objects with simple, inexpensive rectangular images that can be easily created and discarded. This approach uses ordinary rectangular images (like photographs or printed images) instead of specialized calibration targets, making calibration accessible and eliminating the need for expensive equipment.
3Measurement precision
If multiple images of a checkerboard are used, then the measurement precision is improved, but the loss of time and productivity worsen
Solution Approach 1:
The patent segments the calibration process into independent mathematical operations that can be performed on a single image. By dividing the calibration task into extracting rectangular features, computing homography, and deriving extrinsic parameters, the system achieves accurate calibration from one image alone, eliminating the time loss associated with capturing multiple images.
Solution Approach 2:
The patent performs preliminary mathematical model preparation by establishing the projective geometry framework and homography relationships before actual calibration. This preliminary setup enables the system to quickly process single images without requiring multiple captures, thus reducing calibration time while maintaining precision through pre-established mathematical relationships.
Data Source
AI summary
A method for providing a camera calibration includes recovering geometric information from a single rectangular image, obtaining intrinsic and extrinsic construction information of a camera based on the recovered geometric information, obtaining a shooting position and real geometric information of the camera from the obtained intrinsic and extrinsic construction information of the camera.