juliaashk's profile - activity

Hello,

So right now I am trying to write some code so that I can read from 6-8 webcams simultaneously. The eventual goal is to calibrate them and do some other image processing. I should also mention that I am using Visual Studio 2010 on my Windows 7 machine.

Right now I am using cvCreateCameraCapture which works splendidly for 1-2 cameras, and even works for 3 cameras when 2 of them are matching USB cameras and one of them is my built in laptop camera. The problem comes around when I start trying to read from 3 identical cameras.

i.e. here is my code until the line it breaks at: CvCapture* capture0; CvCapture* capture1; CvCapture* capture2;

capture0 = cvCreateCameraCapture(0);
capture1 = cvCreateCameraCapture(1);
capture2 = cvCreateCameraCapture(2);

assert( capture0 != NULL );
assert( capture1 != NULL );
assert( capture2 != NULL );

I was reading on some forum that there might be some issue with overloading the USB ports due to the fact that the webcam images are uncompressed. However, all of these posts referenced solutions using 2003 Windows libraries that are no longer accessible.

So my specific questions are:

1. Is there a better function to be using than cvCreateCameraCapture?
2. Is there a way to convert raw streaming uncompressed camera feeds to compressed, and how would one do this (all solutions I saw were for Linux)?

Thanks in advance for any assistance you might be able to provide

With regards to setting linker configurations. I had the same problem too at first.

What I did was I created a brand new project. Then I had trouble getting into property manager.

If you are not already viewing the property manager you can go to Tools -> Setting -> Expert settings. After that, you will see View -> Property Manager option.

Then click on the arrow to expand the project and right click on Debug. Click on Add new Property Sheet. Once created you can Change the linker properties on this sheet. You can use this sheet in other projects by right clicking debug and clicking add existing property sheet.

Does this help at all?

It looks like the developer repository can be found at the following link: http://code.opencv.org/projects/opencv/repository

The latest updates can be picked up from here as soon as they are checked in.

Also you can go to: http://code.opencv.org/projects/opencv/issues?query_id=5

It is a list of all currently open bugs, who they are assigned to.

Best of Luck!

Hello,

I am new to C++ and OpenCV. I installed OpenCV on Windows 7 following the instructions from the tutorial on this site as best as I could.

I have been using Microsoft Visual C++ as my IDE to run through many of the tutorials and to get an idea of how the OpenCV functions work.

Recently I tried doing the "Finding Contours in Your Image" tutorial from the following link. http://docs.opencv.org/doc/tutorials/imgproc/shapedescriptors/find_contours/find_contours.html

When I run the script I get the following error message:

"Unhandled exception at 0x00000000 in Contours.exe: 0xC0000005: Access violation."

It seems like something is going wrong with the vector definitions (contours and hierarchy) when findContours tries to use them.

Any ideas how to fix this?

Is there possibly some linking issue with DLL's or an incorrect installation? So far everything else has been working.

Thanks for your help,

Julia

PS: Also would someone mind explaining to me how these vector definitions work? vector<vector<point> > contours; vector<vec4i> hierarchy;

what is Vec4i?