OpenCV Q&A Forum - RSS feedhttp://answers.opencv.org/questions/OpenCV answersenCopyright <a href="http://www.opencv.org">OpenCV foundation</a>, 2012-2018.Mon, 14 Sep 2020 21:21:45 -0500How many IP cameras can openCV handle for real time processing?http://answers.opencv.org/question/235138/how-many-ip-cameras-can-opencv-handle-for-real-time-processing/I am doing camera viewing and controlling the project. I have to work with more than 128 cameras and they all have to process in real-time. So how many cameras can be streamed live (real-time) through OpenCV? What will be the deterioration in the performance? And what kind of hardware support does this project need?Virtuall KinggMon, 14 Sep 2020 21:21:45 -0500http://answers.opencv.org/question/235138/Use OpenCV for Virtual reality video with 2 camerashttp://answers.opencv.org/question/230126/use-opencv-for-virtual-reality-video-with-2-cameras/I have a very basic virtual reality helmet and two 4K USB cameras.
I would like to be able to record a video with these two cameras by using Opencv in Ubuntu and C++ in order to playback it on my smartphone on the helmet.
I'm currently able to record and to stream images (in two different windows) coming from my two cameras in this way:
#include "opencv2/opencv.hpp"
#include "opencv2/highgui/highgui.hpp"
using namespace cv;
using namespace std;
int main()
{
VideoCapture captureL("/dev/video0");
if (!captureL.isOpened()) cout << "Problem on the left camera" << endl;
VideoCapture captureR("/dev/video2");
if (!captureR.isOpened()) cout << "Problem on the right camera" << endl;
Mat imageL, imageR;
while (1)
{
captureL >> imageL;
captureR >> imageR;
imshow("OriginalL", imageL);
imshow("OriginalR", imageR);
waitKey(1);
}
captureL.release();
captureR.release();
return 0;
}
I would like to know if there is any document that I can study to understand how to implement the features I need.
Is there any similar project or library which I can use as starting point?
The video format should be similar to the ones used for youtube videos, I took a screenshot as example.
![image description](/upfiles/1589365010521679.jpg)
Thank you!marcusbarnetWed, 13 May 2020 05:11:28 -0500http://answers.opencv.org/question/230126/I have system with three camera. I have R and T matrix between C1 & C2 also between C2 & C3. How to transform a point from first camera to third camera?http://answers.opencv.org/question/212998/i-have-system-with-three-camera-i-have-r-and-t-matrix-between-c1-c2-also-between-c2-c3-how-to-transform-a-point-from-first-camera-to-third-camera/I have three cameras (C1, C2, C3). I have calibrated C1 & C2 as one stereo pair(System-1) and C2 & C3 (System-2) as another stereo pair. So in results, I have rotational and translation matrix between C1 & C2 also C2 & C3. After successful reconstruction, I have one 3D point say P(X, Y, Z) using system-1. So my question is how to transform Point P in all three cameras?HardikdavaWed, 15 May 2019 15:50:52 -0500http://answers.opencv.org/question/212998/Find 3D coordinates of unknown amount of points with multiple camerashttp://answers.opencv.org/question/211877/find-3d-coordinates-of-unknown-amount-of-points-with-multiple-cameras/ So I have a number of cameras laid around a room to track the objects insie the room. The objects uses reflective markers, and from these markers the cameras record their respective x-y image coordinates of the markers they see, the raw pictures are discarded. I have the parameters of these cameras and I want to find the 3D coordinates of these markers.
I was thinking about calculating them through triangulation, but to do that I need to know how many markers I have, and which coordinates recorded in each camera belongs to which marker. I do not have that information. Is there an algorithm to find that out?klWuSun, 21 Apr 2019 10:00:36 -0500http://answers.opencv.org/question/211877/Estimate object pose using multiple camerashttp://answers.opencv.org/question/208716/estimate-object-pose-using-multiple-cameras/Hello!
***TL;DR
I need a function similar to solvePnP(), but that would be able to estimate the pose of a model using information from multiple cameras instead of only one camera***
I am trying to find the pose (rotation and translation) of a simple object covered with markers, using n cameras placed around the object.
The pose of each camera is known: I already have a matrix Ci for each camera i such as for a point X=(x,y,z,1) in real world coordinates, Pi*X gives me the coordinates of that point in the camera's coordinate system.
The object I am trying to estimate is composed of m points, and I know the position of each of them in the object's coordinate system.
I am already able to find the object's coordinates in the plane of each cameras.
So if I put all this together, for each point j seen in a camera i I get this:
**sij * Pij = Ci * A * Xj**
where:
**sij** is an unknown scalar (it is here because we don't know how far from the camera the point found is) that multiplies the projection of the point j on the camera i *(unknown)*
**Pij** is the coordinates of the point j projected on the camera i: (x',y',1)T *(known)*
**Ci** is the matrix that describes the rotation and translation of the camera i *(known)*
**A** is the matrix I'm looking for, it describes the transformation between the object's coordinate system and real world coordinates *(unknown)*
**Xj** is the point j in the object's coordinate system: (x,y,z,1)T *(known)*
I will typically see 4 different points on 3 different cameras (the 12 points found are all differents), which would give me a set of 12 of those linear systems.
How do I find the matrix A that satisfies the best this set of linear systems ?
This problem looks like something that could be solved using DLT (https://en.wikipedia.org/wiki/Direct_linear_transformation), but I'm not able to transform my systems to fit the form shown on this wikipedia page.
*My question is similar to this one : http://answers.opencv.org/question/131660/multi-view-solvepnp-routine/,
but the answer there does not solve my problem because it requires that the points used to resolve the pose of the model are seen in multiple cameras.*Nick_Mon, 11 Feb 2019 15:46:00 -0600http://answers.opencv.org/question/208716/