Hi,  Daniele

The USB1 can't handle a high frame rate at high resolutions (like 640x480=
x 30
fps) because of the high volume of data. So to solve that problem they
compress the video with some "side effects" like image quality loss, and
consecuently you'll loose quality in the captured patterns and in the
tracking. =


Sometimes the USB1 cameras use low image quality sensors because they can=
't =

get good quality anyway, and as you can see this have a double negative e=
ffect
in ARToolKit.

I don't use any USB2 hardware but i do use a Firewire camera. The slowest=

machine I have to test it is a Linux system on a PIII 700Mhz and it works=
 VERY
GOOD at 640x480x30 fps with no compression. The USB2 is a little faster t=
han
the Firewire, so in theory you'll get the same results than with the Fire=
wire
with no problems.

I just have to say that I couldn't use a Firewire camera at 640x480x30 in=

Windows, and a few days after i saw this problem i changed to Linux. I be=
live
it was problem with the capture driver of windows so maybe the problem wi=
ll
persist with USB2 video (but maybe not).

If anyone could post more about this "speed capture/windows" problem it w=
ould
be great.


Have fun =

Pedro Cervantes

"Daniele Pagliani" <postadani@h ..........> wrote:

> Hi all,
> I'm palying wit Artoolkit (2.65vrml) on windows and I've deal with low =
frame

> rates (10 fps). Sometimes I tried to increase the fps but i notice =

> difficulties to have an output with a good feedback (I was moving the m=
arker

> quickly with my hand, but the output had a hight delay). Now I'm planni=
ng to

> use a USB 2.0 camera in order to reach 20/30 fps. is it possible? Does =
it =

> exit a upper limit using usb cameras in conjunction with ARToolkit?
> =

> I saw other mails about this argument in the past, but no reply. I hope=
 =

> somebody can reply to me.
> =

> =

> Thanks.
> =

> Daniele
> =

> _________________________________________________________________
> Personalizza MSN Messenger con sfondi e fotografie! =

> http://www.ilovemessenger.msn.it/
> =

> =

Daniele Pagliani wrote:
> Hi all,
> I'm palying wit Artoolkit (2.65vrml) on windows and I've deal with low 
> frame rates (10 fps). Sometimes I tried to increase the fps but i notice 
> difficulties to have an output with a good feedback (I was moving the 
> marker quickly with my hand, but the output had a hight delay). Now I'm 
> planning to use a USB 2.0 camera in order to reach 20/30 fps. is it 
> possible? Does it exit a upper limit using usb cameras in conjunction 
> with ARToolkit?
> 
> I saw other mails about this argument in the past, but no reply. I hope 
> somebody can reply to me.
> 
> 
> Thanks.
> 
> Daniele
> 

I have no experience with vrml version of ARTookit, but we are working 
with ARToolkit2.61 rendering OpenGL objects in very low performance 
plataform (Geode 300Mhz-SBC) and figuring out a way to improve the 
system to have a reliable embedded application.

How fast CPU are you using ??

We are using it with Linux and V4L, and a patched version of ARToolkit 
to load YUV420P image format and AMDXP-2000Mhz 256Mbytes DDR-RAM; we 
reach 15 fps anyway after 800Mhz.

BTW, the ov511-like USB camera also work with that stuff since driver 
version 2.27 to linux kernel 2.6.7.

In our main case, Geode 300Mhz, the limited frame rate comes from the 
CPU, 0.9 fps with original ARToolkit stuff and resolution of 352x288.

We could increase the frame rate arroud 100 % (2 fps), simply by change 
the argDrawMode to AR_DRAW_BY_GL_DRAW_PIXELS instead of default, then it 
does "raster" the real image pixels instead of render it as texture, 
that is very slow in our video card (MediaGX) without OpenGL set.

And reach arroud 3 fps without show image of real world (see-through 
applications)

Of course, I mean we can play more with ARtoolkit trying to improve the 
performance to use the same stuff in less expensive, portable, mobile 
plataform with low/mid-end cameras; cause the pattern_recognizing  schem 
is not slow at all and do not limit the system as was the common idea, 
at least, my idea before it.

I also miss more comments on this list :|

Is there anybody working on related things anylonger ?

best regards.


-- 
Celso Providelo
cprov@g ...........
Linux user #166906
Gwyddion - http://www.gwyddion.com
GNUsp Project - University of Sao Paulo (USP - Sao Carlos)

Hi all,
I'm palying wit Artoolkit (2.65vrml) on windows and I've deal with low frame 
rates (10 fps). Sometimes I tried to increase the fps but i notice 
difficulties to have an output with a good feedback (I was moving the marker 
quickly with my hand, but the output had a hight delay). Now I'm planning to 
use a USB 2.0 camera in order to reach 20/30 fps. is it possible? Does it 
exit a upper limit using usb cameras in conjunction with ARToolkit?

I saw other mails about this argument in the past, but no reply. I hope 
somebody can reply to me.


Thanks.

Daniele

_________________________________________________________________
Personalizza MSN Messenger con sfondi e fotografie! 
http://www.ilovemessenger.msn.it/