imaqtool does not see webcam!

Hi,

My usb camera works fine with amcap and also with matlab on another computer but when used on this computer, it only works with amcap. If i use 'imqreset' or restart matlab then even amcap fails to detect any camera. Although reinserting the camera in the port makes it to start to work with amcap again but it still fails to appear in imaqtool and also generates error while using 'videoinput('winvideo')'. Could it be the usb access problem? Please help me in this regard.

Best Regards, Rafid

Answer 1

[Image Analyst]

Is this a Windows system? If so, does it appear in the "Imaging Devices" category in Device Manager? I believe in videoinput you need to specify a mode which has a resolution, like RGB24_640x480 or something like that.

vid = videoinput('winvideo', 1, 'RGB24_640x480');
src = getselectedsource(vid);
vid.FramesPerTrigger = 1;

[Abu Jawad Rafid Siddiqui]

Yes it appear in the device manager. And it works fine in other windows programs as well as amcap utility. Furthermore, i have also used the same command with device id and image type parameters but all i get is the following error:

vid=videoinput('winvideo',1,'RGB_640x480');

??? Error using ==> videoinput.videoinput at 233

There are no devices installed for the specified ADAPTORNAME. See IMAQHWINFO.

[Image Analyst]

So, forget about your program for the moment, the one where you're calling that. Let's just talk about imaqtool. In the hardware browser, do you see any device modes listed? If so, when you click on one (like I did), does it generate any code for you in the "Session log" panel? If you don't see any modes listed in the hardware browser even though you see a camera in Device Manager, then you'll have to contact The Mathworks to figure out why their hardware browser is not seeing all your imaging devices.

[Avr Azhagan]

my adaptor name is 'dcam' . But my inbuilt camera is not getting recognized. Im using an inbuilt dell camera.

This is the error im getting;

>> x=videoinput('dcam',1); Error using videoinput (line 233) There are no devices installed for the specified ADAPTORNAME. See IMAQHWINFO.

[Madhura Suresh]

Hi Avr Azahgan,

If you are using the inbuilt laptop webcam, its most likely to work with the 'winvideo' adaptor. What is the output of:

imaqhwinfo winvideo

This should list the camera. Then try,

vid = videoinput('winvideo','1');

The command that you are using uses the dcam adaptor. This will work if your camera supports the dcam interface, which I'm pretty sure the dell inbuilt camera won't.

Madhura

[ayse satilmis]

thanks a lot!

Answer 2

[beyza bilici]

Hello, my inbuilt camera also don't get recognized. the output of :

imaqhwinfo winvideo

Invalid ADAPTOR specified. Type 'imaqhwinfo' for a list of installed ADAPTORs. Image acquisition adaptors may be
available as downloadable support packages. Open Add-Ons Explorer to install additional adaptors.

I am using matlab 2017b, while I was using 2010 it did recognize my camera. The same codes do not work on the newest version of MATLAB

[Image Analyst]

Did you use the hardware explorer to install the webcam add on and the "Image Acquisition Support Package for OS Generic Video Interface" and the "MATLAB Support Package for USB Webcams"?

[beyza bilici]

No I didnt at that time, after a while I noticed that and solved the problem. Thank you

Answer 3

[José Carlos Ferreira]

Hello.

I have a Bison webcam that is working in my Debian 9 laptop. However, after I install usb wecam support package and Image Aquisition Toolbox, MatLab can't still "see" my webcam.

This is what command window shows:

>> imaqhwinfo linuxvideo

ans = 

  struct with fields:

       AdaptorDllName: '/home/........./Documents/MATLAB/SupportPackages/R2016b/toolbox/imaq/supportpackages/genericvideo/…'
    AdaptorDllVersion: '5.1 (R2016b)'
          AdaptorName: 'linuxvideo'
            DeviceIDs: {1×0 cell}
           DeviceInfo: [1×0 struct]

>> webcam
No webcams have been detected. Please ensure the webcam is connected to the system.

Then I did:

>> dev_info=imaqhwinfo('linuxvideo', 1)
Error using imaqhwinfo (line 143)
There is no device with the specified DEVICEID.

I also tried:

>> vid = videoinput('linuxvideo', 1)
Error using videoinput (line 233)
There are no devices installed for the specified ADAPTORNAME. See IMAQHWINFO.

but still no way of detecting my webcam.

[José Carlos Ferreira]

Well, apparently Matlab can see the adapter but can't see the webcam. I tried with v4l2ucp and with cheese an the webcam is working as expected.

Can't figure out what am I doing wrong!

Answer 4

[Hakan Basargan]

Installing Image Acquisition Toolbox Support Package for OS Generic Video Interface might solve your problem :

https://www.mathworks.com/matlabcentral/fileexchange/45183-image-acquisition-toolbox-support-package-for-os-generic-video-interface

Answer 5

[riya mathew]

I am using a usb webcam and need to take pictures on it. I installed the required support package (MATLAB Support Package for USB Webcams) But this package is not providing me with an adaptor name in order for me to take the snaps using the usb webcam. However, when I installed another support package (Image Acquisition Toolbox Support Package for OS Generic Video Interface) it took snaps from the laptop's inbuilt camera. But I need to take snaps on an externally mounted Webcam. Kindly suggest a solution

[Image Analyst]

If your OS sees your camera (in Windows, check Device Manager under the Imaging Devices category) then it should show up in imaqtool. Does it? Post a screenshot of imaqtool.

[Cillian Hayde]

The solution for me on windows 10 was,

device manager -> Action -> scan for hardware changes

Then I returned to Matlab and ran the commands

devices = imaqhwinfo("winvideo");
devices.DeviceInfo

Hope this helps other folks who have this issue.