webcame Capture Problem

[Mar-Q]

Hello,

I am trying to take pictures from webcam throw Labview , Labview can detect the camera but the problem is that it doesn't capture and display the picture

I have installed the IMAQ USB driver and I have tried 3 types of webcames but the same broblem is present

I have used the Labview webcame Library,

and also the example attached

Can any help me solving this Problem ?

Thank you

Mar-Q

[Mar-Q]

Any help Please

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[VGA_CD-ROM]

Hi qurrr,
Your VI worked fine on my system with my Creative Live! USB camera without requiring any modifications. Are you getting any errors when you try to access your camera?

Are your USB cameras DirectShow compliant? They need to be in order to access them using IMAQ for USB (for example, is the "USB Camera" string indicator you have on the front panel filling in with the name of your camera OK?).

Another possibility is that your are disabling the "snapshot" property of the Image Viewer on your front panel, but in the VI you posted it was still enabled properly. If it was disabled, then when you dispose of the image, it would clear the image display because they would both be pointing to the same space in memory. Please take a look at the following KnowledgeBase articles to see what I mean there:

KB 3NDH344Y: IMAQ Image Display Indicator Changes Throughout Execution of VI

KB 3NRFH84Y: Image Display Refreshing in LabVIEW

To ensure your image display would be updated before your dispose is called, you could change your simple VI to be like the screenshot I've included, where you put the display indicator in a flat sequence with the IMAQ USB Close VI, so that you force it to get called before the IMAQ Dispose VI.

Message Edited by VGA CD-ROM on 02-27-2008 03:10 PM

[Mar-Q]

Hi VGA

thank you very much for your replay and sorry for my late replay Iwas busy past days ....

I'm using the Creative Live! USB camera also in my project !!! and I used other cameras to be sure that the problem is not from the camera

I have no errors in the program and while accessing the camera

and the programe can identify the camera by displaying the name of the camera in the pront panel filling space

and when I have tried the camera on vision assestance by acuiring image throu USB also it works fine

the snapshot property is enabled, I have checked that.

I dont know where is the problem !!

I will try to modify the VI and do it like the Picture attached but Iim some how begginer with LabView

I willattach a picture of how the frontpanel look like in excution time

Thank you for your help

Mar-Q

[Mar-Q]

I have modified the Vi as yours also no picture is displayed !!!

[Mar-Q]

can this be a camera problem ? how can I know that it's direct show filter

this is my camrea :

http://us.creative.com/products/product.asp?category=218&subcategory=219&product=13979

also I have tried those :

http://www.logitech.com/index.cfm/webcam_communications/webcams/devices/254&cl=au,en

http://www.labtec.com/index.cfm/gear/details/EUR/EN,crid=30,contentid=714

still the problem is present !!!!!! 😞

[VGA_CD-ROM]

Hi Mar-Q,
What happens if you try using the USB Acquisition Express VI? Does that work? How about if you take your working Vision Assistant and convert it into a LabVIEW VI using Tools » Create LabVIEW VI?

[Mar-Q]

Hi VGA

thank you for your Help

Finally it does work 🙂 the problem was in camera name

but now I am using some thing like this  analog to usb converter:

http://www.brickhousesecurity.com/ad02a.html

I can capture frome window movi maker or other window program

but in vision or lab view it cannot detect the camera when I press USB aquire

and this message comes out : the setting for the camera is not valid

you can see that in the attached file and after pressing OK the camera setting becom inactivated "gray" you can see in second pic

this is not like the previous problem because the labview was detecting the camera just i hade an error in my VI

how can i fix that  !!!

thank you

Mar-Q

[VGA_CD-ROM]

Hi Mar-Q,
I'm curious about how the camera name was wrong to begin with, since you were using the IMAQ USB Enumerate Cameras VI to get all the names anyway. Did you have more than one USB camera connected?

For the RCA-to-USB adapter, I don't know of a way to guarantee it would work in LabVIEW or Vision Assistant... did you have to install the software that comes with it to access it in Windows Movie Maker, or did it work right when you plugged it in? And what happens if you try using the USB Acquisition Express VI in LabVIEW to try acquiring from it?

[Mar-Q]

Hi VGA

I had an error defining the camera name in the VI , I didn't write the exact camera name

the  attache VI is working .

Yes I had to install the software that comes with it to access it in Windows Movie Maker

I have tried using the USB Acquisition Express VI in LabVIEW  but i had a problem of not detecting the camera

thank you for your help