Calibrating camera requires accurate calibration targets. Understanding calibration boards is crucial if you are looking to pre-calibrate your camera. This article delves into what are calibration boards and targets. Let's get started.
What Are Calibration Boards?
Our calibration boards
are made using high-resolution prints directly on flat boards such as glass or strong Dibond to produce accurate results during a calibration process.
AprilTags is a visual fiducial system, useful for a wide variety of tasks including camera calibration. If you need to pre-calibrate your camera with a calibration test target to be as accurate as possible, our custom AprilTag targets are just what you need!
They are printed directly onto a rigid, premium 1/8 inch Dibond, making them the perfect calibration boards to calibrate cameras.
Direct to substrate printing at 1000 dpi with an anti-reflective surface "flood white" authentic matte finish allows for easy and accurate detection in your computer vision pipeline.
Our ChArUco calibration targets are printed directly onto a premium 1/8 inch Dibond. This makes them the perfect calibration boards to calibrate cameras. In ChArUco targets, fields are uniquely encoded, which makes it possible to calibrate using a partly occluded or with a non-ideal target location.
Because of its optical performance and physical robustness, the direct-to-substrate printing at 1000 dpi with an anti-reflective surface "flood white" authentic matte finish allows for easy detection and accurate computer camera calibration.
The checkerboard provides a sampling of points in a plane that can easily be detected automatically. This saves the user time by not having to manually identify calibration points. A series of images or frames must be captured with the checkerboard in different positions and orientations throughout the space to be calibrated.
Why do it? Well, calibration refers to estimating extrinsic and intrinsic parameters of a pinhole camera. Typically, the representation of this camera parameter is in a 3×4 matrix referred to as the camera matrix.
Kalibr targets are suitable for multi-camera and IMU calibration using the popular Kalibr calibration software. Kalibr aims at solving multiple problems, including:
- Multiple camera calibration: multiple camera calibration refers to the intrinsic and extrinsic calibrations of a camera system with overlapping fields of view
- Rolling shutter camera calibration: this involves full intrinsic calibration of rolling shutter cameras. The full intrinsic calibration includes projection, distortion, and the shutter parameters
- Visual-inertial calibration (Camera-IMU): visual-inertial calibration refers to the spatial and temporal calibration of an IMU w.r.t camera system
MVTec Halcon is calibration software used for machine vision with an integrated development environment (HDevelop) used globally. By applying a Halcon calibration board with circular targets plane of matrix gridding type and functions library, a camera calibration algorithm and accuracy analysis are established. This method is simple, and it improves the calibration precision and computation speed.
What Are Calibration Targets?
A calibration target is a physical object with a detailed calibration pattern and identification. It acts as a standard deviation in adjusting and measuring the color, thickness, and size of the nominal grid square and layout of the square grid intersections.
We have different calibration patterns you can choose from, like AprilTag, ChArUco, Checkerboard, Kalibr, Calibration, and Halcon.
What Is Camera Calibration in Computer Vision?
Camera Calibration is also known as camera resectioning or as geometric camera calibration and involves estimating a pinhole camera's intrinsic and extrinsic parameters.
The representation of a camera is in a camera matrix, usually a 3x4 matrix. You can use the intrinsic and extrinsic camera parameters to correct lens distortion, determine the camera image center, measure the focal length, or determine the accurate size of an object in world values.
Why Should I Choose a Professional Calibration Board?
Professional calibration boards have accurate calibration targets that ensure improved measurement results. Our calibration targets have Dibond features with better calibration accuracy and robustness and offer superior flatness.
They will significantly improve measurement accuracy and the calibration results. The boards are also water and temperature-resistant.
Camera Calibration and Targets
In the calibration process, targets are essential when calculating a transformation using a geometric model. For instance, you can rely on a known location of patterns and the patterns' positions on camera calibration targets on a calibration board design, such as ChArUco, Asymmetrical
, or AprilTag targets measured from the scene's imaging to determine the camera model.
Get High-Precision Calibration Boards
What are the benefits of using a calibration board?
A calibration board is a great way to ensure that your measurements are accurate. By using a calibration board, you can calibrate your equipment to ensure that your readings are precise. This can help you to avoid mistakes and ensure the accuracy of your data. Additionally, calibration boards can help you to troubleshoot problems with your equipment.
How do I use a camera calibration board?
To use a camera calibration board, you first need to create or download a calibration pattern. This can be done using software such as OpenCV or MATLAB. You then need to print the calibration pattern and attach it to the calibration board. The calibration board should be placed in front of the camera so that the camera can capture the calibration pattern. The calibration pattern will then be used to calculate the camera's parameters.
What should I consider when choosing a calibration board?
When choosing a calibration board, you should consider the size of the board, the material it is made from, and the accuracy of the measurements. The board should be large enough to accommodate the parts you are calibrating, and the material should be sturdy enough to withstand repeated use. The accuracy of the measurements is important for ensuring that your calibrations are accurate.