Snap aquisition

[rgouvasiur]

Hello ...

I am new in labview and I have installed LabVIEW 7.1 and Vision assistant 7.1. Since i'll be working with a Webcam, i downloaded the NI IMAQ for USB cameras and installed it, and i already install the USB driver to several extra languages.
At the moment I already get to run the webcam in the labview, but just through the grab aquisition.

I already tried many ways to use the snap and I never got any result. i use also the examples of NI-IMAQ for USB Cameras.pdf to get the snap, but never work. when i try the snap appears only black image. (Image in annex - snap_example )

i got also a pci 1409 and i use a ccd camera (only 256 tones of gray) and appears the same problem, i can´t make the snap aquisition.

By the way somebody knows why i only can make the grab aquisition if i remove the init usb. (Image in annex - init_usb )

Thanks for Help.

[jogmero]

I have no experience with USB cameras on LabVIEW, but have you tried to snap with MAX (Measurement and Automation Explorer), that program who come installed during LabVIEW installation package?  In my experience if you see it on MAX you must see it on LabVIEW.

As I mentioned I am not familiar with USB cameras, but on MAX you must see your camera under option "Devices and Interfaces" and maybe USB and then your camera.

Try it and if does not work so something is wrong with your dirvers installation.

JoGMeRo

[Richard_KEROMEN]

Hi,

You should probably take a look at this post, it may help you...

http://forums.ni.com/ni/board/message?board.id=170&message.id=151242&requireLogin=False

Thanks for contacting us,

Richard Keromen

NI France

[bro]

Hi

I am also looking into using a digital camera for image registration purposes.  I've looked at a few of the options and I'm not quite sure what the best way to go about it is.  My experiment consists of a beam of white/laser light that scans across a tissue sample using scanning mirrors at a 90deg angle to the sample.  Then I would have this registration camera slightly off axis to capture each of the data locations.  Oh and I have Labview 8.0.

Option #1:  Machine vision camera / DV-Cam  :  Seems like overkill
#2:   Regular old point and shoot (USB or FIREWIRE) and then use IMAQ or PTP.   One problem I've run in to is that I can not seem to find a list of directshow compatible cameras.   PTP seems like an interesting choice because I can use a cheap  <$500 camera from Nikon or Canon and then spend about $400 on drivers from HyTek.  Has anyone tried this option??  And if so what kind of read/write speeds did they get?  Has anyone had much luck with webcams?  I should also mention I'm trying to avoid buying a Labview  pci card.

Thanks!
Tim

[ScottSmith]

Re. your comment:  "can not seem to find a list of directshow compatible cameras"

The Allied Vision Technologies family of cameras are DirectShow compatible.   See www.GoAVT.com    AVT is an NI partner.

Re. your next comment: "can use a cheap? <$500 camera from Nikon or Canon and then spend about $400 on drivers from HyTek" ... don't know direct answer to that, but with AVT Guppy at VGA model for $780 (drivers included) you'd come in under your stated price, and with a smaller physical package besides.

Kind regards,

Scott

[pallen]

Bro,

I have used HyTek's PTP and a Nikon D50 camera in a project recently.  

The read/write speeds on this project were not critical, so I've never calculated them.  The images I'm taking are high resolution (6M) and the process they are used in is not time critical.  

For the most part the camera works well with the PTP drivers, even though that particular model was not listed as fully supported.  There have been some problems with crashing that may be a result of this.  

I have also done a little "playing" with an Intel USB web cam.  But I was only able to use the default low resolution settings with LabView.  I also experienced a number of "hard crashes" on my development system while playing around with USB cam.  

My current project will be using 5 Unibrain Fire-i cameras.  http://www.unibrain.com/Products/VisionImg/Fire_i_BC.htm  

We've used these cameras in single cam applications a number of times with success.  

[kostmo]

Pallen,
I also wish to control a Nikon D50 with LabVIEW.  Were you able to activate the shutter with software from HYtek?  You mentioned the camera was not listed as "fully supported" - I have downloaded the HYtek drivers but not had any luck operating the shutter yet...

[pallen]

If by "activate the shutter" you mean acquire an image; Then yes.  I was able to active acquire images immediately using the demo VI.  

Two very important things to consider if you're having trouble.  

1. Windows XP is required.

2. The camera must be put into PTP mode. (Neither of my two cameras were in this mode when new)  On the D50 this can be a little tricky.  You'll know when the camera is in PTP mode by how Windows recognizes the device when you plug it in.  If the camera is connecting as a remote storage device, (like a USB key) it is not in PTP mode.  In PTP mode, you'll be able to activate the camera shutter and take pictures directly from Windows Explorer.  

If you've satisfied these two things and the Demo VI still won't work for you; I'd suggest that you send an email to Hytek.  


Good luck.