Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Admin on September 15, 2007, 06:18:42 PM
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Im thinking about getting a nice webcam (nothing el-cheapo) to use for my future computer vision projects . . . and of course to webcam with friends online . . .
Anyone have recommendations?
something under $100, and is easy to interface (such as source code already out there), preferred . . .
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I've always trusted CNET for their recommendations... http://reviews.cnet.com/4566-6502_7-0.html?tag=dir&sort=edRating7+desc
Looks like the Logitech QuickCam Fusion is the best
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Is this for Windows or Linux?
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windoze . . .
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I use the Microsoft Lifecam VX-3000 and it hasnt really disappointed me at all... Ive had it for a while now and Im pleased with it. It wasnt too expensive either which is good. Only thing that made me skeptical about it was that it bares the MS name... Id lean more towards a logitech though... I like Logitech :D
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Im going to echo the recommendation for the logitech's
I have used the logitech quickcam pro 5000 which costs about $80
It has 30fps, 1.2MPixels. It also has a fixed focus which can be bad depending on the application.
I think the FOV was about about 35 degrees in one direction and 45 degrees in the other (its been a while and I could be confusing that with the pro 4000).
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Hi!
Do you have software along with those webcams which allows you to set the exposure time when taking still images? Also, can you control the timing of when still images are taken, or is there a lag and variations in that lag? Or you using them for computer vision projects (is anyone in the world using webcams for computer vision?)
I want to be able to calculate the position and speed of moving objects in a set of images, and would need precision in timing of taking still images. I need to know very well when each image was taken to calculate time intervals between images. If they are taken with constant intervals, that's fine for me even if the interval is unknown. And I need short exposure times (1/10 is too slow, I need 1/30 or better) to get sharp edges on the objects. Long exposures blurs them.
Some digital compact cameras allow remote controlling from a PC with such control. However, I don't know of any software for controling webcams in a similar way. That's kind of funny since webcams are made for realtime PC-usage, and I'm sure it exists somewhere out there. Maybe you know of some webcam/software combination which might help me?
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Roborealm is the tool you are looking for
http://www.roborealm.com/ (http://www.roborealm.com/)
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I have some $70 creative that I got for $35 after rebate.
that thing is a trooper.
it fell with my monitor and the metal part of the usb plug bent, and the thing didn't works, but now it works, but shows everything with a shade of purple.
what are your thoughts on going dual purpose, and get one of those mini wireless cameras? use for robots and then connect to the pc for conferences
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Forgot to mention that I bougt a webcam.
I ended up getting the Logitech QuickCam Communicate STX 1.3MP
Effective Pixels 640 x 480 30fps USB Interface WebCam
I got it since its only $35, works really well in indoor low lighting, and the mic sound is great too :D
I toyed around with it in RoboRealm for a bit, but nothing serious. Just tracking red objects . . .
http://www.newegg.com/Product/Product.aspx?Item=N82E16826104066&Tpk=26-104-066
(http://images10.newegg.com/NeweggImage/ProductImageCompressAll200/26-104-066-02.jpg)
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I'll take a look at roborealm, thank you!
But my impression was that it works with videostreams. I need still images taken at distinct and known times. And I need to control exposure times, can roborealm do that? (okey, I'll check!)
::)
I've written my own image processing code, which is specialized on my specific task and like 100 times faster than I think Roborealm would be with its conventional general purpose image processing code (because I only analyze about 2% of the pixels in any given image). I've tested my code on still images which I've taken in non-realtime, and it works perfectly.
My problem is to get still images, with short exposure times, taken at known times and sent in (near) real time. If the images arrive with a second or two delay is okey, but it is critical that I know pretty exactly when the pictures were taken. I cannot calculate speeds and predict positions unless I have good timings. 1 or even 0.5 frames per second would work, but the higher the better.
I'm new to the camera world and I'm surprised that this seems to be a problem. But I've probably just haven't found the right place yet. Most people seems to wanna use their webcams only for actually looking at the images with their human eyes, so they say stuff like: "This is a good webcam, because its images look pretty!" How boring!!!
;D
And I know nothing at all about webcam exposure times (shutter time). A guy who actually performs consumer tests of webcams said that they vary from 1/1000 to 1 seconds. It seems to be something which manufacturers keep secret. Does 30 fps video mean 1/30 exposure time for still images? I've heard that they change exposure time automatically with the light conditions. I don't want that. I want sharp images, even if they get too dark for the eye (my color statistics can deal with it). I don't want wireless, I don't want any video conferencing. I simply want sharp well timed still images!
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what is really needed is a cam where you can say
take picture
get picture data
process data
repeat
rather than trying to work with a stream...
there are some that do this but they are expensive really. Im sure that it just needs smething like the sx lcd drivers to retrive data rather than just set it.
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But my impression was that it works with videostreams. I need still images taken at distinct and known times. And I need to control exposure times, can roborealm do that?
you can use roborealm with any video source, streaming or movie files
I plan to use my webcam for indoor robots with varying poor lighting, so I need it to autoadjust to light settings. I didn't need anything high resolution or high frame rates since my vision algorithms need to be fast (real time!) and tend to throw away most data from the images anyway.