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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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Which openCv function can be used to compute BEV perspective transformation given a point coordinates and the camera extrinsics/intrinsics?

I have the 3x3 intrinsics and 4x3 extrinsics matrices for my camera obtained via cv2.calibrateCamera() Now I want to use these paramenters to compute the BEV (Bird Eye View) transformation for any given coordinates in a frame obtained from the…
Maf
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How to calibrate camera using react native?

We have requirement of capturing photo from app, but for that external light source is attached near to camera of phone. Using which we have to calibrate camera for getting better image. Is there any code snippet or methodology which can be use to…
Ashay
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How does cropping an image affect camera calibration intrinsics?

I have the following camera matrices for resolution 1600x1300 M1 [3x3] = [ 1.3964689860209282e+03, 0., 8.3190541322575655e+02, 0., 1.3964689860209282e+03, 5.9990987893769318e+02, 0., …
vishnukumar
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Why would cv2.findEssentialMatrix return a 12x3 array?

When using the function cv2.findEssentialMat, the output for E is a 12x3 array, when it should be a 3x3 array. By definition, essential matrices are 3x3. I have tried altering the options/parameters, including method, threshold, and prob, but…
Jeremy
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Why is the opengl projection of a model not giving the exact same results as the opencv projection?

I'm working on a project where I use cv::solvePnP to get the camera pose and use this pose to project a 3D model in an OpenGL window. I used this link to go from opencv intrinsic and extrinsic matrices to opengl mvp matrices. The projection seems to…
user6138759
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Camera Calibration in Natural Marker tracking

Is it necessary to calibrate the camera if I were to implement a natural marker tracker? Actually I don't quite get the idea of camera calibration although I have read that it is required for augmenting 3d/2d objects onto the image feed.
aaronljx
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Camera calibration across multiple images

Taking one camera and moving it around to take two images of the same object, from a different viewpoint, one should be able to compute a matrix that relates these two scenes. In OpenCV, how is this accomplished?
soxarered
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Is it possible to compute intrinsic and extrinsic camera parameters from a given camera projection matrix?

If I have a 3x4 camera projection matrix, can I compute all or just some of the individual intrinsic and extrinsic camera parameters, i.e., focal length, principal point coordinates, rotation angles (roll, yaw and tilt), and translation vector? If…
ZhengTang
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OpenCV(3.4.1) Error: Assertion failed (dims <= 2 && step[0] > 0) in cv::Mat::locateROI

I will post my code and the exception after explaining my issue. So basically, I'm making a program where the end goal is to be able to calibrate a fisheye camera which is then on a rtsp stream from the camera that will be recorded via zoneminder…
tommy61157
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RaspiCam fisheye calibration with OpenCV

I am trying to calibrate RaspiCam Fisheye lens camera with OpenCV. I am using Python example code and the cheesboard row and column numbers are also correct but somehow I can not get a successful result. I have tested with a lso much of photos below…
mesutpiskin
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Camera Source (Google Mobile Vision) returns rotated image on some devices

I have the open sourced code for the Google Mobile Vision - CameraSource and this is the method I call to click a photo : cameraSource.takePicture(); In the open sourced version of CameraSource.java, the method for determining screen orientation is…
V.Bhat
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OpenCV + Python: Calculate stereo reprojection error

I want to do something similar to this question, but for stereoCalibrate() instead of calibrateCamera(). That is, compute the reprojection error for a stereo camera calibration. My reduced example looks like this: import cv2 import numpy as np def…
TheBender
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Optimizing the stereo calibration process on multiple cameras

Background: For simplicity, I have 3 Cameras. Each one of them is calibrated by its own (its interstice parameters are known and accurate enough) They all share almost the same view. I want to use this system of 3 Cameras for 3D reconstruction. I…
Humam Helfawi
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OpenCV: Why projectPoints() is giving me weird results?

Why is my code snippet giving me weird results for projected points? //Generate the one 3D Point which i want to project onto 2D plane vector points_3d; points_3d.push_back(Point3d(10, 10, 100)); Mat points3d = Mat(points_3d); //Generate…
Mirnyy
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Low RMS value when calibrating single camera, while high RMS value in stereoCalibrate

I am trying to calibrate a stereo setup consisiting of two identical Canon EOS60D's, which i will be using to do Photogrammetry. To calibrate cameras i am using a high precision circlegrid pattern plate. I was able to detect centre points of…
the_parzival
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