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Questions tagged [camera-calibration]

In Computer Vision, camera-calibration is the process of finding the true parameters of the camera that produced a given photograph or video. Usually, the camera parameters are represented in a 3 × 4 matrix called the camera matrix.

Usually we say a camera is calibrated when we know the Intrinsic Parameters.

Source: Wikipedia

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opencv charuco camera calibration won't undistort properly

I'm in some trouble getting the charuco camera calibration to work. To the best of my knowledge, I do everything right, but the final undistorted images are very much more warped than expected. It does work with a 4x4 board, but then the area that…
Jochemspek
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How to retrieve AVCameraCalibrationData from photo output on iOS?

I'm looking to retrieve the lens distortion coefficients (note: not focal length nor principal point) associated with a photo that I capture on an iOS device. From my understanding, the only way to do so on a iOS device is to use…
The Obscure Question
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Transformation of 3D objects related to vanishing points and horizon line

I'm trying to computing the exact prospective transformation of a 3D object starting from a vanishing points and horizon line of a picture. What I want is, fixed the vanishing points and horizontal line of a picture, I want rotate and skew an 3D…
hyperzone
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Why does the camera calibration in opencv-python takes more than 30 minutes?

I was trying to replicate this camera calibration code. When I run my script, the calibration process won't stop for about 30 minutes (I expected the intrinsic camera matrix for the output). What is wrong with my code? Why does the calibration…
rendchevi
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How does cv2.projectPoints actually work?

I'm trying to write my own implementation of cv2.projectPoints just for practice, and my implementation is not behaving as expected. I'm assuming a pinhole camera with no distortion, so all I'm doing is applying the following equation to all of my…
Carpetfizz
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Camera calibration, reverse projection of pixel to direction

I am using OpenCV to estimate a webcam's intrinsic matrix from a series of chessboard images - as detailed in this tutorial, and reverse project a pixel to a direction (in term of azimuth/elevation angles). The final goal is to let the user select a…
Florent
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Convert between MATLAB stereoParameters and OpenCV stereoRectify stereo calibration

I wish to convert a MATLAB stereoParameters structure to intrinsics and extrinsics matrices to use in OpenCV's stereoRectify. If I understood http://docs.opencv.org/2.4/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html and…
Gnubie
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How to "undistort" a crop of image in OpenCV?

I am working with an IDS camera with wide fish-eye. It is 2D-camera, but I need just the line in the middle. I got how to calibrate the camera: I can get undistorted images. My problem is that I need quick computation. So I'm trying to find a way,…
Anton
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Kinect v2: Spatial resolution/ depth resolution / camera calibration

For my application, I analyzed the spatial resolution of the Kinect v2. To analyze the spatial resolution, I recorded a perpendicular and planar plane to a given distance and converted the depth map of the plane to a point cloud. Then I compare a…
JavaNullPointer
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OpenCV - store camera matrix and distortion coefficients as Mat

I've used the sample OpenCV program to calculate the camera matrix and distortion coefficients from my camera and produced an xml file with the relevant data. I'm trying to use it through the undistort function but I'm not sure how to store the…
Colin747
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OpenCV Issue with findChessboardCorners

I also asked this on the OpenCV forum, am trying my luck elsewhere. I'm using OpenCV 3.0 in Visual Studio Professional 2013. So I'm trying to calibrate a camera using the tutorial code in calib3d and this tutorial. I keep getting the same error…
Max
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Minimum number of chessboard images for Stereo Calibration and Rectification

What is the minimum number of chessboard image pairs in order to mathematically calibrate and rectify two cameras ? One pair is considered as a single view of the chessboard by each camera, ending with a left and right image of the same scene. As…
Chris
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Camera Calibration Intrinsic Matrix what do the values represent?

So I did a camera calibration using the checkerboard and the matlab camera calibration toolbox. So the Intrinsic Matrix that I obtained for that particular session is as follows: Intrinsic Matrix: [349.3601,0,0;0,349.7267,0;258.0883,210.5905,1] I…
Ali P
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Calculating 3D world point from 2D image point using OpenCV

I'm developing application for iOS. I'm using the camera matrix according to the book Mastering OpenCV. In my scenario I have a well known box. I know its real dimensions and I know exactly its corner's pixels. Using this information I calculate the…
user2743760
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Essential Matrix from Fundamental Matrix in OpenCV

I've already computed the Fundamental Matrix of a stereo pair through corresponding points, found using SURF. According to Hartley and Zisserman, the Essential Matrix is computed doing: E = K.t() * F * K How I get K? Is there another way to compute…
JuaniL
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