calibration images?
Where are the calibration images referenced here? http://docs.opencv.org/3.2.0/d7/d21/tutorial_interactive_calibration.html
View ArticleCallibrating a bunch of cameras - Can I use a linear rail robot?
Hi Guys, I need to calibrate a bunch of cameras, and I was wondering if the opencv camera calibration could work if I build a simple robot with a screen and a linear rail to move the camera. Something...
View ArticleInteractive calibration frame rejected
So I'm trying to use opencv_interactive-calibration with the following parameters: opencv_interactive-calibration -ci=4 -h=5 -w=8 --pf=defaultConfig.xml --of=cameraParameters.xml -t=charuco My config...
View ArticleMemory error during calibration of IR camera
Hello, I'm trying to calibrate my IR camera (Optitrack NaturalPoint) using the camera calibration module of OpenCV 3.0.0 and Visual Studio 2015. I used an assymetrical circle grid. I'm using...
View ArticleRaspberry pi v2 camera matrix
Hi all, I am working on Raspberry pi camera v2 (8Mp) & I want to extract its parameters (camera matrix/intrinsics matrix). This is what I got after running OpenCV camera calibration on 46 pics...
View ArticleHow to use camera calibration in Java
Hi, I haven't calibrated my camera as of yet, but I'm planning to just run a C++ program in some way, and grab the necessary matrices. Now, my question is sort of similar to [this...
View ArticleIncreased Reprojection Error from Chessboard Calibration
So, I have written a script that performs chessboard calibration and the reprojection error I get is always greater than 1.3-1.5 pixels, even though the calibration parameters are correct (except the...
View ArticleCamera Calibration
For tarffic survaillence appilications using static cameras installed in highways, which is a better approach to calibration, manual or automatic? Can anybody give an idea on how to start working on...
View ArticleFisheye lens calibration using OpenCV returning zero valued distortion matrix
I am doing all the usual for calibrating a fisheye lens, I have 22 images that return `true` using the `findChessboardCorners()` function, I concatenate the points into a `vector>` which I use for...
View ArticleHow to create a matrix and make it a copy of the camera matrix?
Hello, I have retrieved the calibration parameters for my camera, meaning that I have the camera matrix and the distortion vector. However, now that I have those, I want to undistort my image using...
View ArticleI have footage but not the camera: how am I going to correct the lens...
I should have thought this would be a staple of any image library, but I've been having a rough time figuring out how to do it with OpenCV. (I am a new user, trying to figure things out for the first...
View ArticleFocal length from calibration parameters
I am trying to calibrate my camera (sony alpha 6000 20mm lens) using open CV. In the parameters list, I can find the focal length coefficient as 5192. How can I calculate the corresponding focal...
View ArticleGetting zero ROIs from getOptimalNewCameraMatrix
Hi folks, I am attempting to do some calibration on my fisheye PiCamera, now stuck on this func `getOptimalNewCameraMatrix`, the code works when fisheye lens removed, but fails when it is mounted....
View ArticleSmartphone camera manufacturing precision
Does anyone of you have an experience with how precise smartphone cameras are manufactured on a given higher-end smartphone model (I mean phones like Samsung Galaxy S 5/6/7, iPhones etc.)? I need to...
View ArticleFisheye distortion correction using Omnidir namespace - change of perspective
I have been able to correctly calibrate a 180 degrees FOV camera (fisheye), i.e. I have been able to extract the distortion and camera matrices using the omnidirectional model, so I used the...
View Articleinteractive charuco application fails...
Hi, i have built the sample app `opencv_interactive-calibration.exe` and it will run ok on a webcam (although every frame is rejected, I assume the webcam is too low res) I have a higher resolution...
View Articlecalibrate-camera-charuco sample error
I am trying to use the opencv calibrate-camera-charuco sample, from here: https://github.com/opencv/opencv_contrib/blob/master/modules/aruco/samples/calibrate_camera_charuco.cpp I have it building but...
View ArticleRe-distorting a set of points after camera calibration
I am working on a project in Python to calibrate a small thermal camera sensor (FLIR Lepton). Because of limited resolution initial distortion removal is not very exact. By using an iterative method I...
View ArticleHow does resizing an image affect the intrinsics?
Hi there, i have calibrated a camera using images at 1280 * 720. the intrinsic data is: 1280 72033d 6.5700301862152855e+02 0. 6.4669706479436286e+02 0. 6.5700301862152855e+02 3.4711751174913059e+02 0....
View ArticleHow to use Multi-camera Calibration modules?
Hi guys I need some help, I did a stitching code for 4 GoPro camera input, but I need more accurate camera calibration result especially the camera pose. So I found there is a Multi-camera Calibration...
View ArticleDifferent undistorting results (first rotate, then undistort OR first...
Hello, i don't know why, but i get different results if i first rotate the image and undistort it, or if i first undistort and then rotate it. There is a very small difference at both results... (In...
View ArticleHow can I keep horizontal and vertical FoV after undistortion
Hi everyone, I've used initUndistortRectifyMap() and Remap() to undistort image, but I have no idea how to crop the ROI I want. I want it keep the region of original horizontal and vertical FoV, I've...
View ArticleError using fisheye callibration in python binding OpenCV 3.2.0
System information (version) OpenCV => 3.2 Operating System / Platform => Linux / Ubuntu 15.04 Compiler => Python 3.4.3 (default, Mar 26 2015, 22:03:40) [GCC 4.9.2] on linux When I try the...
View ArticleStrange values for matrix camera and distortion values
I am trying to calibrate a fisheye camera. In order to do that I load a video take with that camera and takes frames where appears a cheesboard pattern. In order to find patterns I use: bool found =...
View ArticleIs calibration doing what I expect?
We are using ArUco markers to calculate the real-world size of objects in an image. Here's a sample test image:  I find the outer corners of the ArUco...
View ArticleUnderstanding Calibration
As far as I have understood, the calibration of a camera lens is done, so that the image sensor data distortion can be rectified before being stored as a file. I can think of intensity as one of the...
View ArticleUndistortPoints randomly returning huge values
Hi all, to let me put everything in context, let me describe what I am doing/trying to do. I have a multiple camera setup which I calibrate using OpenCV. The images obtained from the cameras contain a...
View ArticleHow many pictures do I need to prepare for solvePnP and which coordinate...
I'm using a checkerboard or circles to use solvePnP. In this case, how many pictures do I need to prepare? Only one picture is fine because it includes several points? I saw some articles recommend to...
View Articlebad results with findCirclesGrid
Hello everybody, I'm trying to write a program for a camera-calibration using the 4x11 asymmetric circle grid. I use a camera with 3840x2750 pixels. Although the pattern is recognized by the program...
View Articlecalibration board tracking
Hi all, I know the x, y, z values of all the points on this calibration board very precisely. I want to calculate a homography between the found pixel locations of the large dots, and their...
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