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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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Camera pose estimation (OpenCV PnP)

I am trying to get a global pose estimate from an image of four fiducials with known global positions using my webcam. I have checked many stackexchange questions and a few papers and I cannot seem to get a a correct solution. The position numbers I…
Gouda
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Python Opencv SolvePnP yields wrong translation vector

I am attempting to calibrate and find the location and rotation of a single virtual camera in Blender 3d using homography. I am using Blender so that I can double check my results before I move on to the real world where that is more difficult. I…
amartin7211
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Re-distort points with camera intrinsics/extrinsics

Given a set of 2D points, how can I apply the opposite of undistortPoints? I have the camera intrinsics and distCoeffs and would like to (for example) create a square, and distort it as if the camera had viewed it through the lens. I have found a…
Andy
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finding the real world coordinates of an image point

I am searching lots of resources on internet for many days but i couldnt solve the problem. I have a project in which i am supposed to detect the position of a circular object on a plane. Since on a plane, all i need is x and y position (not z) For…
user3417020
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How to verify that the camera calibration is correct? (or how to estimate the error of reprojection)

The quality of calibration is measured by the reprojection error (is there an alternative?), which requires a knowledge world coordinates of some 3d point(s). Is there a simple way to produce such known points? Is there a way to verify the…
Alex Kreimer
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Meaning of the retval return value in cv2.CalibrateCamera

as the title says, my question is about a return value given by the calibrateCamera function from OpenCv. http://docs.opencv.org/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html I have a functionnal implementation in python to find…
David
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Camera calibration with OpenCV - findChessboardCorners returns false

I try to calibrate my camera. I run some example but all of them don't find corners of chess board. Finally, I use this question's code, but it can't find corners.There is a image below. I use it to find corners. I find a command on web for this…
zakjma
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OpenCV: get perspective matrix from translation & rotation

I'm trying to verify my camera calibration, so I'd like to rectify the calibration images. I expect that this will involve using a call to warpPerspective but I do not see an obvious function that takes the camera matrix, and the rotation and…
Dave
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OpenCV - How to get real world distance from a 2D image using a chessboard as reference

After checking several pieces of codes, I took several shots, found the chessboard corners and use them to get the camera matrix, distortion coefficients, rotation, and translation vectors. Now, can someone tell me which python opencv function do I…
Pablo Gonzalez
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Is there a camera calibration matrix database?

Is there a free-access database containing camera calibration parameters (camera matrices, intrinsic and extrinsic parameters) for the most popular devices? I'm particularly interested in mobile-phone cameras or tablets with fixed focal length more…
ButterDog
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Kinect intrinsic parameters from field of view

Microsoft state that the field of view angles for the Kinect are 43 degrees vertical and 57 horizontal (stated here) . Given these, can we calculate the intrinsic parameters i.e. focal point and centre of projection? I assume centre of projection…
Aly
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OpenCV extrinsic camera from feature points

How do I retrieve the rotation matrix, the translation vector and maybe some scaling factors of each camera using OpenCV when I have pictures of an object from the view of each of these cameras? For every picture I have the image coordinates of…
Martin Hennig
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How to use opencv bundle adjustment

I have calculated 5 camera matrices (c1, ... c5), camera matrices are calculated by placing a 3D object at 5 different positions and for each position I have calculated camera matrix (and camera is constant). Camera matrix is calculated using SVD…
Deepak
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OpenCV fisheye calibration cuts too much of the resulting image

I am using OpenCV to calibrate images taken using cameras with fish-eye lenses. The functions I am using are: findChessboardCorners(...); to find the corners of the calibration pattern. cornerSubPix(...); to refine the found…
NoShadowKick
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OpenCV stitch images by warping both

I already found a lot questions and answers about image stitching and warping with OpenCV but I still could not find an answer to my question. I have two fisheye cameras which I calibrated successfully so the distortion is removed in both images.…
DamBedEi
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