OpenCV Q&A Forum - RSS feedhttp://answers.opencv.org/questions/OpenCV answersenCopyright <a href="http://www.opencv.org">OpenCV foundation</a>, 2012-2018.Thu, 03 May 2018 12:04:21 -0500OpenCV calibration vs. Matlab calibration accuracyhttp://answers.opencv.org/question/190809/opencv-calibration-vs-matlab-calibration-accuracy/ Hello,
So I've programmed a simulation to project a plane onto a flat screen.
![image description](/upfiles/1525366480996756.png) ![image description](/upfiles/15253665357539681.png)
The red circle is my "camera", the blue is the object being projected, and the green are the 2D image point projections.
So, I know exactly where my camera is in my simulation.
I used OpenCV calibrateCamera() and used the returned camera matrix to find the camera location coordinates, and then compared that with the actual one, and my normalized distance error is .000301162. I tried increasing the amount of iterations for my term criteria, but it just converges at this number.
Then I also used MATLAB estimateCameraParameters(), and my normalized distance error was 1.76E-12.
To summarize:
Source error for OpenCV = .000301162.
Source error for MATLAB = 1.76E-12.
This is a significant difference, and I was wondering if there were any settings or additional functions in OpenCV that will make my values turn out the same as MATLAB's, and if there is any reason to why this is like this. eoyster417Thu, 03 May 2018 12:04:21 -0500http://answers.opencv.org/question/190809/type and size of calibration pattern for most accurate resultshttp://answers.opencv.org/question/19442/type-and-size-of-calibration-pattern-for-most-accurate-results/Hi!
I want to use OpenCV for accurate measuring - so the first step should be the best camera calibration possible.<br />
There are three types of camera calibration patterns:
- chessboard
- symmetric circles
- asymmetric circles
Does anyone have some experience which type is the most accurate?<br />
What is the advantage of sym and asym. circle pattern, if any?
Another important parameter is the relative size of the pattern in the camera image.
Are there any rules for the minimum size? For example the pattern should cover 25% of the image or something like that?<br />
Is there any minimum radius in pixels for the circles/width of the squares in the resulting image?
Thanks!efanucarSun, 25 Aug 2013 08:59:10 -0500http://answers.opencv.org/question/19442/