All imaging systems inherently exhibit errors in their representation of the real world. These discrepancies may arise from tolerances in mechanical construction, sensor misalignment, and optical aberrations, ultimately leading to inaccuracies in the arrangement of information captured in the image. This inaccuracy is commonly referred to as distortion. Camera calibration is a process that determines the complex projection function that characterizes image distortion, allowing it to be removed. While it is primarily utilized in applications requiring precise geometric and depth measurements, it is also beneficial for users seeking a distortion-free image. Edmund Optics^® has partnered with Quartus Engineering to offer a camera calibration service leveraging Edmund Optics^® extensive catalog of cameras & lenses & Quartus' patented calibration technology called PixelTraq. This innovative architecture automates all facets of the calibration process and employs advanced optimization models to ensure that your imaging system is calibrated for your specific application.

Calibration services are currently available only for our TECHSPEC^® Fixed Focal Length lenses and compatible cameras, as these units can be securely fixed in place and do not require movement to focus. At this time, we do not offer calibration services for S-mount configurations. On the relevant product pages, you will see a "Calibration Services" tab that will take you to our PixelTraq Camera Calibration Services Quote Tool where the camera, lens, illumination color, desired camera model, working distance, and f/# can be selected. Our team of Machine Vision Sales Engineers will be alerted once the form is complete and they will reach out to you shortly to further discuss your application. The more information you can provide our team of engineers about your application needs, the better we can support getting you the appropriate calibration settings.

* Spectral Data available upon request

Please note that approximately 10 additional days of lead-time are required for calibration.

• Precision Calibration: Includes certificate, parameters, and secure server storage
• Seamless Integration: Access calibration via QR code; integrate via API
• Imaging System Support: Expertise in hardware selection and simulation

Your order will include a fixed imaging system securely assembled at your selected focus, along with a calibration certificate, epoxy-staked at points of adjustment to prevent drift. All calibration files are securely stored on Quartus’ servers and can be easily accessed using the QR code on your certificate or hardware. The calibration certificate includes detailed information on intrinsic and extrinsic parameters, a distortion deviation percentage chart, angular error, and surface error values—all of which can enhance the accuracy of your system. To fully leverage this calibration data, Quartus provides an API that you can integrate into your application or use as a starting point for your custom code. More information on camera calibration & how to apply your calibration model can be accessed via the QR code link at the bottom of the provided calibration certificate, or through Quartus Resources.

High accuracy imaging systems need recalibration at a frequency determined by your application. For applications susceptible to environmental change, machine vibration, and high usage, it is best to routinely evaluate the performance of the machine and recalibrate when accuracy drops. As a general guideline, many imaging systems benefit from recalibration every six months to a year.

Imaging systems have intrinsic and extrinsic factors which share valuable information about how the image is formed. Intrinsic factors tell us how light is refracted through the imaging lens and onto the sensor. In contrast, extrinsic factors tell us the orientation and position in the physical world. Ultimately, calibration is the process of deriving a mathematical model that traces the light rays from the 3D real world scene into 2D mapping of the pixel array along the sensor. The PixelTraq Calibration process allows us to measure the intrinsic factors in the system and remove errors caused by lens refraction. This calibration method is particularly well-suited for applications such as three-dimensional inspection, autonomous robotics, and medical imaging, where precise depth perception and spatial frequency representation are critical.

Figure 1: PixelTraq offers flexible configuration options for various camera parameters, such as field-of-view, working distance, backlight illumination color, target density, chart design, electronic interface, and camera model.

It is common for customers to try a DIY calibration with a printed checkerboard target and an open-source training model. The process to do this involves fixing the camera in a set position and then taking images of a target through your entire point of view being sure to overlap target features in the image. Once you have enough feature overlap to map out a point cloud in the Field of View (FOV), you can begin the process of calibration. Inherently your calibration model is limited by the quality of the data used; without traceable and calibrated targets the potential for error significantly increases. For additional details on the differences between the open source method and Pixeltraq, please refer to the Introduction to Camera Calibration whitepaper. PixelTraq fully automates the calibration process using a test rig that captures thousands of data points within a matter of minutes. This data is subsequently analyzed by an optimization algorithm to identify the optimal camera model, and point density to meet your specific requirements. Furthermore, PixelTraq evaluates reprojection errors within the trained models to ascertain the best fit for your application.

Figure 2: A Quartus employee uses a specialized testbed for calibration and checks to be sure that all overlapping target features have high contrast across the entire FOV.