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RSS >  fps or resolution or mpixels????
MuraD #1 15/08/2007 - 23h13

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hello folks.

for some1 who's about to buy a new webcam to try freetrack, what would be more important?

fps?
i see there are a variety of models which can go from 15 fps to 60 fps.

resolution / mpixels?
also it's same with the resolution, 640x480 to HD resolutions???!?

which combination would guarantee a near real time response time?

thanks in any advance.
Schyz #2 16/08/2007 - 03h41

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I think is not only fps but also latency. Is good to have a smooth animation of our movements, but is not funny that the fighter pilot roll his head 2 seconds after us.

About resolution, I have a good track with VGA res so the investment in a SVGA camera perhaps don't worth it. And is always better use a lower res to get better latency and CPU usage.

Check the field of view too, most of webcams are not designed to watch you in movement.

Anyway, I bet a low latency camera with a nice field of view has good resolution and fps. And, of course, it's expensive  ^ ^
Kestrel #3 16/08/2007 - 06h02

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I'm trying to make Freetrack work well on cheap 30fps 320x200 webcams but the following should be considered if you want better results:

Real time response is limited by fps, a high webcam fps is the holy grail of head tracking but can also eat into your cpu. Some webcams give you control of the compression quality, allowing you to increase the frame rate with a reduction in image quality, which is less demanding on your cpu.

More expensive, higher quality webcams, generally have less image noise than the cheaper ones, this means you can use a smaller floating deadzone while maintaining a stable view, giving you better responsiveness.

A wide angle webcam is recommended to allow you more head movement.

The Freetrack v2.0 GUI is not designed for resolutions greater than 352x288, the next version probably won't be either. Using resolutions higher than this consumes a large percentage of your CPU for negligable improvement in tracking quality.
MuraD #4 16/08/2007 - 11h38

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gentlemen, thanx a lot for your replies and keeping em clear,, much appreciated!! (insert beer smiley here) : l o v e :   : l o v e :
einsena #5 28/08/2007 - 03h52

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I'd say it's best to have a camera with high FPS on high resolution.

High FPS gives you smoothness

High resolutions gives you great field of view hence the higher the resolution the larger area that could be tracked

Megapixels is essentialy higher resoulution it gives extra clarity (in theory)
e.g 1.3 Megapixel is 1280*1024 resoulution, wheres 640*480 is only 0.3 Megapixel. in theory if the camera sensors are good(lens, CCD, CMOS, etc) then the higher the resolution the bigger and clearer the picture. but here's the thing freetrack does not need real good picture clarity to work

so id recommend the following for freetrack useage
FPS>resolution>Megapixel
Kestrel #6 28/08/2007 - 04h07

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einsena @ 28/08/2007 - 05h52 a dit:


High resolutions gives you great field of view hence the higher the resolution the larger area that could be tracked



For full field of view you need to use the webcam's native resolution or an even multiple of that resolution. For example, a 640x480 webcam can halve the number of pixels for 320x240 and quarter them for 160x120 while maintaining full fov.

Using 320x240 with a 352x288 webcam results in a cropped fov.

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