Real time vision with USB2?

[Jizzard]

Hey guys,

I am stuck deciding on a method of image acquisition.

My project requires real time imaging, but it's on a netbook, so anything but USB is out. The ethernet is only 100mbit so no gige.

I have tryed a few comsumer level USB cameras I have lying around here and all seem to have about half a second of latency in any lighting condition. Is there any solution for me?

[BruceAmmons · Accepted solution]

I tend to avoid vision acquisition with USB.  I don't know what the limitations are.  I know most consumer webcams are not good enough quality for machine vision.  There are some industrial USB cameras you might want to look at.

Can you put a firewire card in your netbook?  That would probably be your best option, since there are a large number of firewire cameras available and they are very easy to use.

Bruce

[Jizzard]

Unfortunately no firewire/expresscard.  I have looked at industrial USB cameras and it seems to be my only choice, although they are priced far higher than firewire equivalents.  I guess I will work with what I can!  Thanks for your response!

[BruceAmmons]

Costwise, it might be cheaper to buy a different laptop/netbook that has an expresscard or firewire option.  Are you strongly committed to the netbook you already have?

Bruce

[Jizzard]

For now I will have to stick with this setup.  It will be awhile before I have the funds to change it.  I assume I will go with a Firewire camera when I do though.

[pkozik]

If your laptop has a PCMCIA slot (which most do) you can buy a firewire or GigE adapter for below 80 USD.  The PCM1000 from Linksys supports 7K packet sizes for GigE cameras:

http://www.linksysbycisco.com/US/en/products/PCM1000 

The quality of your laptop will still heavily influence the performance of any machine vision camera, firewire or GigE, nevertheless you will have much better support for these interfaces from NI compared to USB.

[DanRichards]

Hi Jizzard,

I saw this thread and wanted to answer one aspect of your question. LabVIEW uses the Microsoft DirectShow driver to interface with DirectShow-compliant USB Cameras. The Real-Time operating systems we use on our Real-Time targets are the Ardence Phar Lap Embedded Tools Suite and WindRiver VXWorks, which would not have DirectShow. For deterministic applications, you'll need to use a different data transfer method, like firewire or GigE, and be very aware of all possible jitter in image processing applications.

Best of luck!

Dan

[tsinks]

Point Grey has a USB camera with a high end sensor in it.  It also can be triggered externally if you need some synchronization.

http://www.ptgrey.com/products/chameleon/Chameleon_datasheet.pdf

Todd Sinks