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	daperl	2011-04-12 , 15:36
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Originally Posted by ysss

This one takes into account the user's face position (and distance?) to render a much more accurate and realistic 3D...

True, but look at the face recognition portion, he's finding the circumscribing rectangle, which allows for a simple depth calculation. He's not really showing us the original face locking. Following a linearly moving object once you've found it changes calculations by orders of magnitude. And lastly, he's moving that pad slowly; not much acceleration.

In a previous life I was involved with realtime multi-processor/multi-sensor array DSP for tracking bad guys and the things they throw at you.

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Bratag	2011-04-12 , 15:36
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Originally Posted by Snoshrk

Not sure if anyone has posted this here yet....

Looks like the WiFi only Galaxy tab is available NOW! for $350

at least Tigerdirect has them...

Good news for those of us wanting an N800 replacement (ie sans cellular modem).

Still leaning towards a rooted/CM7 Nook Color

Just got CM7 running on my nook color ... it is awesome sauce. Only downside is that I miss the standard nobo ereader app. The one from the appstore cant handle kids books etc

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	ysss	2011-04-12 , 15:53
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Originally Posted by daperl

True, but look at the face recognition portion, he's finding the circumscribing rectangle, which allows for a simple depth calculation. He's not really showing us the original face locking. Following a linearly moving object once you've found it changes calculations by orders of magnitude. And lastly, he's moving that pad slowly; not much acceleration.

The effect is really good tho! (Reminds me of the first time I saw parallax 2D game)
They should put this in on all 3D apps!

In a previous life I was involved with realtime multi-processor/multi-sensor array DSP for tracking bad guys and the things they throw at you.

Pictures, anecdotes, anything... stat!

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	daperl	2011-04-12 , 16:13
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Originally Posted by Capt'n Corrupt

Thanks!

Mine was just speculation. Can you share a link to the source?

The guy doesn't supply any code, but he published these videos of n900 head tracking almost a year ago:

http://johanneskuhlmann.de/projects/facedetect#videos

In the first video, he could have made the head moving animation much smoother if he called me.

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	daperl	2011-04-12 , 16:36
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Originally Posted by ysss

Pictures, anecdotes, anything... stat!

But then I'd have to kill you.

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	ysss	2011-04-12 , 16:39
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Originally Posted by daperl

But then I'd have to kill you.

just blame it on assange!

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	Capt'n Corrupt	2011-04-12 , 18:04
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Originally Posted by daperl

The guy doesn't supply any code, but he published these videos of n900 head tracking almost a year ago:

http://johanneskuhlmann.de/projects/facedetect#videos

In the first video, he could have made the head moving animation much smoother if he called me.

Just out of curiosity, how would you have changed the original (N900) implementation to make it smoother?

I could take some guesses...

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etuoyo	2011-04-12 , 18:53
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Moved to a new country and tried to get 3G internet on my tab. Have not had any luck even after requesting settings from mobile network provider and installing settings. On N900 I could get it to work without any issues. Any tips?

On a separate but somewhat related issue I have noticed that when I switch on my Tab it seems to manufacture an internet connection from somewhere. This was happening before I put a sim in so is clearly some kind of wireless access. When I switch on the device I receive push email and some facebook status messages and have also received whatsapp messages. But when I search for wireless networks I don't find any. Anyone have any ideas what could be causing this spooky occurence.

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	daperl	2011-04-12 , 20:43
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Originally Posted by Capt'n Corrupt

Just out of curiosity, how would you have changed the original (N900) implementation to make it smoother?

I could take some guesses...

Along with accelerometer/gyro config values, I would add three more:

A time interval: i.e. 1 / Frames Per Second (FPS)
A min allowable movement per time interval
A max allowable movement per time interval

Using these values, combined with the deltas of both time and head tracking, you could smooth the movement, and you would also make the code immune to the GPU's speed.

Something like that. And maybe you could do a little better by using 2nd order variables like an acceleration delta (not to be confused with the accelerometer delta).

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	Capt'n Corrupt	2011-04-12 , 21:12
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Originally Posted by daperl

Along with accelerometer/gyro config values, I would add three more:

A time interval: i.e. 1 / Frames Per Second (FPS)

A min allowable movement per time interval

A max allowable movement per time interval

Using these values, combined with the deltas of both time and head tracking, you could smooth the movement, and you would also make the code immune to the GPU's speed.

Something like that. And maybe you could do a little better by using 2nd order variables like an acceleration delta (not to be confused with the accelerometer delta).

Yes, this would work. I would include interpolation (perhaps this is what you meant by 'smooth the movement') between frames and set a best-guess based on these accumulated values at some point beyond the rendered frame -- though close enough not to produce discernible lag or strange 'drifting'. I would definitely use the acceleration delta of many of these to help determine the best-guess. Linear interpolation would be acceptable due to the minuscule time-interval between guesses. I would also determine some sort of weighted average based on the differing values to best determine where the device is related to the head and tick at regular intervals.

I wonder what the power consumption would be for something like this. The camera would have to be running, but I suppose if the majority of tracking code were DSP, it could be done quite efficiently. My only concern would be the facial recognition.

I expect darker faces would also be more challenging due to the reduced contrast.