# \#calibration **URL:** https://forum.opencv.org/tag/calibration/210.md [Latest](https://forum.opencv.org/latest.md) · [Categories](https://forum.opencv.org/categories.md) · [Tags](https://forum.opencv.org/tags.md) --- ## [Rendering a CharucoBoard in my app: how to calculate squareLength and markerLength?](https://forum.opencv.org/t/rendering-a-charucoboard-in-my-app-how-to-calculate-squarelength-and-markerlength/22789)
**Author:** [@snoriman](https://forum.opencv.org/u/snoriman)\ **Replies:** 5\ **Last updated:** [June 29, 2025, 10:15pm UTC](https://forum.opencv.org/t/rendering-a-charucoboard-in-my-app-how-to-calculate-squarelength-and-markerlength/22789 "2025-06-29T22:15:16Z")
I’m working on am app where I generate a CharucoBoard, which I then display on a monitor. I plan to take photos of this board from different angles using a camera, and use those images for camera calibration. The part I… --- ## [Camera calibration for AI object detection](https://forum.opencv.org/t/camera-calibration-for-ai-object-detection/22745)
**Author:** [@snoriman](https://forum.opencv.org/u/snoriman)\ **Replies:** 2\ **Last updated:** [June 26, 2025, 1:27pm UTC](https://forum.opencv.org/t/camera-calibration-for-ai-object-detection/22745 "2025-06-26T13:27:10Z")
I’m experimenting with computer vision and AI models to detect people in a video stream and then map their positions onto a 2D map. Right now, I’m trying to find a solid way to convert the coordinates from the detected … --- ## [initUndistortRectifyMap does not return same undistorted image as manual undistortion](https://forum.opencv.org/t/initundistortrectifymap-does-not-return-same-undistorted-image-as-manual-undistortion/21117)
**Author:** [@zeellos](https://forum.opencv.org/u/zeellos)\ **Replies:** 3\ **Last updated:** [May 31, 2025, 6:10am UTC](https://forum.opencv.org/t/initundistortrectifymap-does-not-return-same-undistorted-image-as-manual-undistortion/21117 "2025-05-31T06:10:04Z")
I have been trying to replicate what initUndistortRectifyMap does for my application. For some reason, when I do manual undistortion, I get different result than using initUndistortRectifyMap. I feel I am following the … --- ## [Camera calibration is very slow for large number of images](https://forum.opencv.org/t/camera-calibration-is-very-slow-for-large-number-of-images/9395)
**Author:** [@Witek](https://forum.opencv.org/u/Witek)\ **Replies:** 2\ **Last updated:** [July 20, 2022, 1:54am UTC](https://forum.opencv.org/t/camera-calibration-is-very-slow-for-large-number-of-images/9395 "2022-07-20T01:54:17Z")
I’m calibrating my camera with a large number of images and it takes forever to calibrate it. Here is a plot of calibrateCamera execution time. It grows very quickly. The code is in C++, in release mode, with OpenMP enab… --- ## [Is there any reason why projectPoints doesn't compute Jacobian for object points?](https://forum.opencv.org/t/is-there-any-reason-why-projectpoints-doesnt-compute-jacobian-for-object-points/18004)
**Author:** [@horth](https://forum.opencv.org/u/horth)\ **Replies:** 0\ **Last updated:** [June 19, 2024, 7:40am UTC](https://forum.opencv.org/t/is-there-any-reason-why-projectpoints-doesnt-compute-jacobian-for-object-points/18004 "2024-06-19T07:40:52Z")
I see that the Jacobian computation is implemented in the internal function and may be computed when cvProjectPoints2Internal is called from cvCalibrateCamera2Internal, but when cvProjectPoints2Internal is called from cv… --- ## [findChessboardCornersSB Fails](https://forum.opencv.org/t/findchessboardcornerssb-fails/14599)
**Author:** [@Neale\_Petrillo](https://forum.opencv.org/u/Neale_Petrillo)\ **Replies:** 1\ **Last updated:** [April 20, 2024, 11:05pm UTC](https://forum.opencv.org/t/findchessboardcornerssb-fails/14599 "2024-04-20T23:05:19Z")
Hello! I’m trying to perform a 2d calibration using the findChessboardCornersSB function and it fails to find the chessboard on what I think should be a pretty straightforward image so I’m assuming I’m doing something ki… --- ## [Inconsistent camera calibration results](https://forum.opencv.org/t/inconsistent-camera-calibration-results/17136)
**Author:** [@AliBuildsAI](https://forum.opencv.org/u/AliBuildsAI)\ **Replies:** 6\ **Last updated:** [April 8, 2024, 12:57am UTC](https://forum.opencv.org/t/inconsistent-camera-calibration-results/17136 "2024-04-08T00:57:02Z")
Hi, I am trying to calibrate a StereoLabs Zed 2 camera and I get inconsistent results. Zed cameras are calibrated themselves, and here is the calibration parameters coming from their SDK: I am trying to calibrate t… --- ## [How to use Eye-In-Hand calibration matrix to get picking point](https://forum.opencv.org/t/how-to-use-eye-in-hand-calibration-matrix-to-get-picking-point/17120)
**Author:** [@Losmi](https://forum.opencv.org/u/Losmi)\ **Replies:** 0\ **Last updated:** [April 2, 2024, 1:45pm UTC](https://forum.opencv.org/t/how-to-use-eye-in-hand-calibration-matrix-to-get-picking-point/17120 "2024-04-02T13:45:35Z")
Hello, I did eye-in-hand calibration with camera calibration before that and now have both transformation matrices. Where I am confused is how to use them to get robot picking point from camera pixel point? I multiply … --- ## [Commercial vs printed calibration boards](https://forum.opencv.org/t/commercial-vs-printed-calibration-boards/16655)
**Author:** [@thisischris](https://forum.opencv.org/u/thisischris)\ **Replies:** 0\ **Last updated:** [March 1, 2024, 3:53pm UTC](https://forum.opencv.org/t/commercial-vs-printed-calibration-boards/16655 "2024-03-01T15:53:15Z")
Hello, I’m trying to calibrate a multi-camera setup for research. Is there a significant difference between using commercial calibration patterns (like Calib.io) or hand-made patterns (printed at home or at a print shop… --- ## [Eye-to-hand calibration](https://forum.opencv.org/t/eye-to-hand-calibration/5690)
**Author:** [@torayeff](https://forum.opencv.org/u/torayeff)\ **Replies:** 12\ **Last updated:** [December 21, 2022, 10:33am UTC](https://forum.opencv.org/t/eye-to-hand-calibration/5690 "2022-12-21T10:33:47Z")
This function cv.calibrateHandEye describes an eye-in-calibration process where camera is attached to a robot arm. I want to do an eye-to-hand calibration where a camera is fixed on a ceiling. My process is as the follow… --- ## [Obtaining the Extrinsic Matrix of a Camera](https://forum.opencv.org/t/obtaining-the-extrinsic-matrix-of-a-camera/6741)
**Author:** [@lightbringer](https://forum.opencv.org/u/lightbringer)\ **Replies:** 4\ **Last updated:** [December 15, 2022, 3:06pm UTC](https://forum.opencv.org/t/obtaining-the-extrinsic-matrix-of-a-camera/6741 "2022-12-15T15:06:31Z")
Hello, I try to learn camera calibration. I used cv::calibrateCamera to obtain intrinsic camera matrix, distortion coefficients, rotation vectors, and translation vectors. How do I get the extrinsic matrix for that camer… --- ## [HandEye Calibration and Nodal Point of camera](https://forum.opencv.org/t/handeye-calibration-and-nodal-point-of-camera/9643)
**Author:** [@markus](https://forum.opencv.org/u/markus)\ **Replies:** 1\ **Last updated:** [July 27, 2022, 7:11pm UTC](https://forum.opencv.org/t/handeye-calibration-and-nodal-point-of-camera/9643 "2022-07-27T19:11:49Z")
Hello, In my setup I have a camera with a tracker mounted ontop of it. For calibrating the camera, I move the camera to various positions around the aruco board and also capture the tracker’s position for each snapshot… --- ## [SolvePnP with Big Object](https://forum.opencv.org/t/solvepnp-with-big-object/9532)
**Author:** [@thnake](https://forum.opencv.org/u/thnake)\ **Replies:** 1\ **Last updated:** [July 18, 2022, 3:43pm UTC](https://forum.opencv.org/t/solvepnp-with-big-object/9532 "2022-07-18T15:43:29Z")
Hello, I have a large object of size 4,5m x 2.5m onto which I want to project AR-Data via solvePnP with high precision. The camera is an iPhone SE 2nd Gen. Due to the large object size, the camera needs to be placed se… --- ## [Which SolvePnp method returns the most accurate translation and rotation?](https://forum.opencv.org/t/which-solvepnp-method-returns-the-most-accurate-translation-and-rotation/8834)
**Author:** [@hamzaabd](https://forum.opencv.org/u/hamzaabd)\ **Replies:** 5\ **Last updated:** [May 23, 2022, 6:07pm UTC](https://forum.opencv.org/t/which-solvepnp-method-returns-the-most-accurate-translation-and-rotation/8834 "2022-05-23T18:07:26Z")
I am trying to do hand in eye calibration with my robot however I am my transformation matrix is not very precise and has a large offshoot in translation, which I think I can fix with offshoots but I want to fix calibrat… --- ## [Translation gives wrong norm in SolvePNP?](https://forum.opencv.org/t/translation-gives-wrong-norm-in-solvepnp/8643)
**Author:** [@hamzaabd](https://forum.opencv.org/u/hamzaabd)\ **Replies:** 1\ **Last updated:** [May 5, 2022, 8:43pm UTC](https://forum.opencv.org/t/translation-gives-wrong-norm-in-solvepnp/8643 "2022-05-05T20:43:03Z")
With the above image called “img2” I am trying to solvepnp so I can use the translation and rotation for the cv.calibrateHandEye() function. When I am using the solvepnp method and get the translation and rotation I g… --- ## [Is there exist a function to "undistort" list of points instead of 2d array (image)?](https://forum.opencv.org/t/is-there-exist-a-function-to-undistort-list-of-points-instead-of-2d-array-image/8022)
**Author:** [@trojek](https://forum.opencv.org/u/trojek)\ **Replies:** 2\ **Last updated:** [March 20, 2022, 4:20pm UTC](https://forum.opencv.org/t/is-there-exist-a-function-to-undistort-list-of-points-instead-of-2d-array-image/8022 "2022-03-20T16:20:47Z")
Hi! Based on documentation of camera calibration one can assume that to get an undistorted image one need to apply the following operations: Get images with chess board, then use cv.calibrateCamera() which returns the… --- ## [ArUco marker in a calibrated image](https://forum.opencv.org/t/aruco-marker-in-a-calibrated-image/7325)
**Author:** [@tisc](https://forum.opencv.org/u/tisc)\ **Replies:** 2\ **Last updated:** [January 28, 2022, 8:55am UTC](https://forum.opencv.org/t/aruco-marker-in-a-calibrated-image/7325 "2022-01-28T08:55:50Z")
Hi :slight\_smile: I am currently working on detecting ArUco markers in an image and then later want to transfer the x/y position of the marker into the coordinate system of my SCARA robot. I have already calibrated the … --- ## [Asking about projector-camera calibration](https://forum.opencv.org/t/asking-about-projector-camera-calibration/4787)
**Author:** [@bubucar](https://forum.opencv.org/u/bubucar)\ **Replies:** 2\ **Last updated:** [August 16, 2021, 9:27am UTC](https://forum.opencv.org/t/asking-about-projector-camera-calibration/4787 "2021-08-16T09:27:51Z")
Hi i have found projector -camera calibration coding in github I would like to ask is there any reference by pictures cause i m not sure what kind of photos have to be taken for the projector calibration.( is it fring… --- ## [Calibration of non-overlapping cameras](https://forum.opencv.org/t/calibration-of-non-overlapping-cameras/4217)
**Author:** [@mikor13](https://forum.opencv.org/u/mikor13)\ **Replies:** 1\ **Last updated:** [July 7, 2021, 6:29pm UTC](https://forum.opencv.org/t/calibration-of-non-overlapping-cameras/4217 "2021-07-07T18:29:51Z")
Hello everyone, thank you for taking time to check this post. My question is the following: I have 4 non-overlapping cameras that make a camera rig and I want to find the relative position of each camera in respect to t… --- ## [Fisheye Chess calibration with fix pixel aspect ration of 1 - HOW?](https://forum.opencv.org/t/fisheye-chess-calibration-with-fix-pixel-aspect-ration-of-1-how/3410)
**Author:** [@Gal\_Oz](https://forum.opencv.org/u/Gal_Oz)\ **Replies:** 0\ **Last updated:** [May 19, 2021, 9:01am UTC](https://forum.opencv.org/t/fisheye-chess-calibration-with-fix-pixel-aspect-ration-of-1-how/3410 "2021-05-19T09:01:27Z")
Hi, I am using a wide-angle lens and the Fisheye model works the best for me. when I doing the chess calibration with the Fisheye class I can’t find a flag that forces the pixel to have an aspect ratio of 1. for the s… --- ## [Quality of hand-eye calibration](https://forum.opencv.org/t/quality-of-hand-eye-calibration/3306)
**Author:** [@davidDS](https://forum.opencv.org/u/davidDS)\ **Replies:** 0\ **Last updated:** [May 12, 2021, 12:21pm UTC](https://forum.opencv.org/t/quality-of-hand-eye-calibration/3306 "2021-05-12T12:21:26Z")
Hello community! Currently I am using the C++ API of OpenCV to perform eye-in-hand hand eye calibration using the TSAI method. However, I was wondering if there exists a method to calculate or determine the quality of t… --- ## [Image dimension measurement - mm per pixel calibration](https://forum.opencv.org/t/image-dimension-measurement-mm-per-pixel-calibration/3196)
**Author:** [@RockB](https://forum.opencv.org/u/RockB)\ **Replies:** 0\ **Last updated:** [May 6, 2021, 7:39pm UTC](https://forum.opencv.org/t/image-dimension-measurement-mm-per-pixel-calibration/3196 "2021-05-06T19:39:52Z")
I am trying to measure dimension of an object in real time using a video feed from a camera. I am working off an single frame/image of the video for now. In order to measure the real (physical) dimensions, I want to fir… --- ## [Stereo Calibration Process for depth estimation with disparity map](https://forum.opencv.org/t/stereo-calibration-process-for-depth-estimation-with-disparity-map/3025)
**Author:** [@Clarence\_Chan](https://forum.opencv.org/u/Clarence_Chan)\ **Replies:** 0\ **Last updated:** [April 28, 2021, 3:50am UTC](https://forum.opencv.org/t/stereo-calibration-process-for-depth-estimation-with-disparity-map/3025 "2021-04-28T03:50:01Z")
Hi OpenCV community, I’m new to OpenCV and stereo photogrammetry. I would like to clarify how the stereo calibration process should be done. I want to check if this process is correct: Capture images on left and righ… --- ## [Why does cv2.findCircleGrid not accept calibration patterns that are ambiguous at 180 degrees?](https://forum.opencv.org/t/why-does-cv2-findcirclegrid-not-accept-calibration-patterns-that-are-ambiguous-at-180-degrees/1939)
**Author:** [@TdiRex](https://forum.opencv.org/u/TdiRex)\ **Replies:** 6\ **Last updated:** [March 11, 2021, 6:45pm UTC](https://forum.opencv.org/t/why-does-cv2-findcirclegrid-not-accept-calibration-patterns-that-are-ambiguous-at-180-degrees/1939 "2021-03-11T18:45:16Z")
I’m trying to use an asymmetric circle grid of dimensions 7 rows and 11 columns to calibrate a camera. However for this dimension or any ambiguous configuration it seems that cv2.findCirclesGrid returns ret=False. Is thi…