I have a built in webcam (HP) and an USB webcam. Whenever I use webcams in OpenCV, the built in webcam is used. However I want use the USB webcam. I tried disabling the built in webcam and even uninstalling the drivers, but after doing that, I get a message saying that no webcams were detected, even though the USB webcam is connected. How can I use the USB webcam instead of the built in webcam? I have searched the net top to bottom and have found no fix.
Thanks
The command CaptureFromCAM accepts an integer as its only argument which specifies the device number to use. Change this number and it will use a different device.
Related
I am doing a project regarding image processing and multiple person counting and was wondering, how exactly can I plug my ION AIR PRO PLUS video recording device (similar to a goPro), and use it as my 'webcam'? Basically, I want to plug it in and then access it via a live feed using Microsoft Visual Studio 2010 and OpenCV, and then do real time tracking of people walking.
What I am struggling with is accessing the external camera from my program. Anyone know how to do this?
The video camera has no wifi, only an hdmi output, RGB cable output and a USB.
Attach the USB cable and instantiate cv::VideoCaputre(0). In Linux local cameras have number indices I think in Windows should be the same.
Peter, In the past I have worked on camera products on Windows XP & 7. On windows usb cameras can be accessed using directshow.
You can implement a directshow filter for people tracking algorithm and fit it in the direct show pipeline soon after your camera plugin.
Here is a link to an application stack that may suit your use case(to give you an idea):
http://www.e-consystems.com/blog/camera/?p=1302
The recent windows operating systems that run WinRT, use a latest framework called MediaFoundation. As its very new there are some limitations we found when we tried to build similar applications.
To quickly see a preview out of your camera, pls google for "graphedit" and install it on a Windows 7 pc. Its a fairly simple tool. You can drag and drop your camera, if directshow is supported, then render its output pin and play for preview.
I do not think this is a standard webcam, it appears to work only as a mass storage device. One thing you can try is removing the micro sd card and connect it to the computer. This works on some cameras.
Assuming this does not work, one option would be to purchase an HDMI capture card. The YK762H PCI-E card costs around $40, and will allow you to use the camera with OpenCV, the videoInput library, or DirectShow.
The other option is to use the WiFi live preview. You would have to figure out the commands sent to the camera. This has already been done with the SJCam wifi cameras, the GoPro models, and Sony cameras such as the QX-10 and HDR-AS100V.
I am trying to get video stream from analog camera connected to usb easycap - in OpenCV C++.
using MATLAB, I can get stream the same approach like for laptop webcam (with changing the index from 1 to 2).
with OpenCV, I can get stream from laptop webcam with index 0.
but when I am trying to get with the camera connected to the easycap (using index 1) , the laptop crashes and get blue screen.
Anyone have done this before?
Thanks
I work on the same device and I also have some BSOD with it.
Do you plug it with the USB extension provided ? If yes, try don't use it.
If your problem is still hapening, it's probably because like me, you use a low quality chinese fake EasyCap. I bought a real one and I haven't problems anymore
If you want to keep your device, you can use it with VideoCapture in python, it works very well and there is no more BSOD
Try using Linux. I tested my code with a fake EasyCAP in windows and I got many BSOD then I built and executed the same code in Linux and it worked.
Linux is driver friendly.
I have been trying to access my analog camera via a EasyCap video capture device. Any code I try only picks the usb webcam or internal webcam. I guess that since video capture device is a video controller, opencv doesnt recognize it as a imaging device.
Can anyone conform if you cannot access analog cameras with opencv via a video capture device.
If so, then what other method can be used.
i struggled with the same problem (in my case within python instead of C++, although I am certain it will be the same root cause) and hope it helps!
the original thread + ANSWER
also relevant XKCD
Even for digital devices, OpenCV isn't good at reading them, it is good at processing them. The library has supply for generic webcams, of course; however it does not supply most of the commercial or industrial cameras.
In short, to decode, you should try using "video for linux" or "video for windows" libraries; or the device SDK itself. Since you are using a video2usb converter, you shouldn't have any problem accessing the analog camera through these software.
I can get an image from web-cam (Microsot HD-3000) with OpenCV and everything works fine, when Xtion isn't plug in USB of computer, but if I just plug it in I get only a gray image from web-cam. Skype can't get image too. Xtion works well with OpenNI 2. I use Windows 7 x86 on my Computer and OpenCV 2.4.0.
The problem you are likely facing is the limitation of the USB bus. Especially Microsoft lifecams are sensitive to this problem as they tend to grab the maximum bus speed they can. If they can't do this they stop working. The solution to this can be either very simple or a little more complicated.
1: Switch around USB plugs. Some mainboards have different USB buses on different ports. By swapping around you might be able to find a configuration that does work for you.
2: Expand your system with another USB bracket. If the solution in 1 doesn't work you're going to have to expand your computer with more USB ports to get around the bus limitation.
3: Use as less USB devices as possible, don't use the ASUS Xtion, or buy a different webcam
i want to built a 3D view of my scene with inputs from at least 3 webcams...presently i am using OpenCV (with C/C++) on Windows 7 32 bit platform and it gives me a maximum of 2 webcam views parallely...i have generated a 3D view with 2 webcams but that is not up to the mark...so i have the following questions...
if i use 3 webcams (2.0) in a USB hub is it possible to access the USB video frames without OpenCV?if yes then how?to keep it simple i can skip the USB hub because my laptop has 3 USB ports...is it then possible?
i have read about LIBUSB library...yet not used it...is it possible to access webcam video frames with this kind of usb library?
how safe is the LIBUSB library?i have read in some forums that if not configured and used correctly the blue screen pops up very frequently...it also runs a chance to damage the usb driver...? is there any other usb library i can use safely?
anyone who have worked on similar usb multiple webcam access stuff or has any idea on this please guide me...any suggestion is welcome...
You can run as many webcams as USB bandwidth allows
If USB bandwidth limit is hit, you are unlikely to resolve this by using certain software library
It might be helpful to lower resolution or start using on-camera compression if such option exists since both reduce USB traffic
More links on USB bandwidth constraint: 2 usb cameras not working with opencv