I thought I share this question before hunting for answers.



I need to be able to capture image every few seconds without human interventions. Previously,I had done this before in DOS and Win32 with Proprietary drivers from the vendor, where a camera is sending analog signals and the card would convert it to digital frames and I could grab a frame and save it.



Now, with new devices, I wonder if I should follow the same route (from Analog to digital), or are there [inexpensive] digital cameras that continuously sends digital frames without the need for conversation and grabbing?

This would be my first choice.



OR



a) Has anyone used any "Video Grabber" (either as USB device or card) to capture single frame picture in .Net?



b) Any suggestion on the brand and model?



c) Is DirectShow my best tool to use, to control the device?



d) Or should I approach it from TWAIN direction



Thanks!

..ßen

We took the TWAIN approach as it does not limit you in the long run.  Also, we use Atalasoft TWAIN imaging tools which have worked very well for us.  They are run-time royalty free and we interface with all types of TWAIN devices from web cameras to high-end scanners.

Thanks Trent;



So by using TWAIN, I have to go the digital route, where the image from device is coming already as "Digital". Or can Twain control capture cards that are fed analog signal?

..ßen

Looks like TWAIN is my best choice to follow. I see several digital camera vendors have support for TWAIN, which means I don't need to convert from analog to digital.



Thanks Trent!

..ßen

As you ahve already discovered, there are a lot of cameras that have TWAIN support.  In fact, most of them do anymore. I went out to Best Buy one day and got several different cameras...some web, and others regular.  I interfaces with all of them using TWAIN and dynamically pulled off the images.

Great info. Thanks!

..ßen

Hey Trent, just wanted to follow up on this with you. As I have done more research on this matter (WebCams), I've learned that TWAIN is being dropped by MS as of Vista and the newer cameras don't support TWAIN anymore. The new support is done by WIA (Microsoft Windows Image Acquisition ). However, there seem to be some problems with the resolution using WIA.



Just wanted to let you know in case you're depending on these devices in your Medical App.



Hope this helps!

..ßen

Do you have some articles regarding this?  Because this has not been my experience so far, including the Vista stuff.  This is another reason to use a 3rd party such as Atalasoft because they should have functionality for this if it is what is coming down the pike.

Hey Trent;





I'm working with Atalasoft as we speak. I was on the phone with the tech support today.



I was also on the phone with Logitech tech support and he was the one who told me supprt for TWAIN is up to XP, with the older version 8.x and for Vista, TWAIN is no longer supported Version 11.x



I had also sent a message to them:





And the replied:





So, now I need to see, what's being std from this point on. Just wanted to keep you in the loop!

..ßen

Yeah, I would like to know what you learn, but I think that fellow is off-base.  There is the new technology (WIA), but I think TWAIN is far from dead   I have been doing a lot of research lately on scanners, and almost all of the newer scanners support ISIS and TWAIN, including the higher-end models in the $5000-$10000 dollar range.  It is rare to run into any scanners that do not support TWAIN.  Also, the most common web cams, such as Creative, on all of their newer models self-install using exclusively TWAIN...including on the Vista OS.  So even though there is new technology to take advantage of, WIA is not supported by most scanners and cameras at the moment, so just like anything else, it will take some time for things to catch up....and there is still a lot of demand for TWAIN.  Obviously we will have to move along with the industry, but it generally takes 2 generations of OS or more for an embedded technology to die.