ISF Logo   IS Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Conspiracies and Conspiracy Theories » 9/11 Conspiracy Theories
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Reply
Old 27th August 2010, 12:33 PM   #201
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Oi, if you two want to have a chat, do it somewhere else please.

And whilst I'm about it...

Quote:
WTC2 is M.I.A.
There is plenty of information on WTC 2 at the911forum.
There is more footage of WTC 1 of better quality that for WTC 2, which may be the cause of your confusion. Just looking at the pictures ?

The purpose of this thread is basically about technical issues related to acceptance of the techniques.

There are many areas for which these techniques are used, which have significant results.

You will have to be patient. It took NIST a while to create the WTC 7 report. There's no rush

Now, if you would kindly remain on topic and restrict yourselves to the technical domain please.

Last edited by femr2; 27th August 2010 at 12:43 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 12:36 PM   #202
Carll68
Critical Thinker
 
Carll68's Avatar
 
Join Date: Jan 2009
Posts: 324
Originally Posted by femr2 View Post
If that's what you think, become a member and sort it out then. I'll buy you a drink (one) when you arrive


You clearly do not have the capacity to consider the phrase *honest research*

Please stay on topic.
And, who is doing honest research? Not you, with the error filled mess spewing over the pages. However, you are clearly implying that NIST did 'dishonest research'..now, get to backing this up kid...why not let your video analysis (scoff) do the scientific talking for you...cuz' thus far' its just mumbling.......
Carll68 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 12:47 PM   #203
carlitos
"más divertido"
 
carlitos's Avatar
 
Join Date: Jul 2009
Posts: 18,112
Originally Posted by femr2 View Post
Oi, if you two want to have a chat, do it somewhere else please.
.....
Now, if you would kindly remain on topic and restrict yourselves to the technical domain please.
Yeah, how dare we discuss how your video analysis relates to 9/11 conspiracy theories....



Again, you'd be better served by skipping all of this nonsense and just taking a logic course.
carlitos is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:06 PM   #204
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Noise Removal

(deleted. noise returned.)

Last edited by femr2; 27th August 2010 at 01:56 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:28 PM   #205
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
Originally Posted by femr2 View Post
If that's what you think, become a member and sort it out then. I'll buy you a drink (one) when you arrive


You clearly do not have the capacity to consider the phrase *honest research*

Please stay on topic.
I'm already a member, thanks. And I disagree about the capacity to do honest research, and i'm as entitled to my informed opinion as you are, sir.

Please note that this is a conspiracy forum, and that measurement of pixels is not relevant in any tangible way to any conspiracy, that I am aware of.

I guarantee you that no amount of your measurements is going to prove or disprove the presence of controlled demolition explosives, the central theme to 9/11 Conspiracy theories.

Now if only you could understand what is relevant.......
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:37 PM   #206
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
Sure, let's get to a technical matter: How does the measurement of pixels relate to 9/11 Controlled demolition conspiracies?

I posit that it does not, as I've noted above. Therefore my opinion stands that this discussion does not really belong on this forum in the first place - and further that insisting that it should be included in conspiracy theories reduces it to a red herring.

Again my conclusion, based on what I've seen on the 9/11 forums, is that this is simply another way to inject the CD conspiracy agenda into an area where it has no relevance at all. Inappropriate and irrelevant.

Further note: Femr2 made a direct reference to the NIST reports 'You will have to be patient. It took NIST a while to create the WTC 7 report. There's no rush'
But the NIST report is a technical and engineering report, not a conspiracy investigation.

Again, by linking your work to the NIST engineering, you are further demonstrating that this is not a conspiracy subject at all, and as such does not belong on this forum.

You can't have it both ways, if you want to be intellectually honest. You've disqualified your own premise.
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:40 PM   #207
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by alienentity View Post
I'm already a member, thanks.
What user ?

Quote:
measurement of pixels is not relevant in any tangible way
It is what the techniques are subsequently used to determine that is the point. And that can only come once said techniques are fully understood, their limitiations and accuracy. Thus this thread

Quote:
I guarantee you that no amount of your measurements is going to prove or disprove
Noted. Surprised that you include both prove and disprove.

Quote:
insisting that it should be included in conspiracy theories
I have said no such thing, and it's not my thread.

You have indicated you are a member at the911forum. Why have you not raised your opinion on this topic there ?

Last edited by femr2; 27th August 2010 at 01:43 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:44 PM   #208
pgimeno
Illuminator
 
pgimeno's Avatar
 
Join Date: Feb 2009
Location: Spain
Posts: 3,324
Originally Posted by alienentity View Post
ETA I suspect that the graphs Femr2 is generating will be used as some kind of 'proof' of controlled demolition by his 'inside job' friends - they certainly look impressive and sciency, not unlike the nice graphs produced by Jones/Harrit et al. which 'prove' the presence of nanothermite.
Data is data. It can be used by both sides of the discussion. E.g. Jim Hoffman has put a load of information which has been useful to both sides; the Pentagon eyewitness testimony comes to mind as an example. I don't see why it has to be different in this case.
__________________
Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.
pgimeno is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:44 PM   #209
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
I humbly suggest that, were Femr2 interested in maintaining the relevance of this thread to conspiracy topics, and wanted to demonstrate that the WTC7 collapse was indeed true to the model of explosive controlled demolition, that he would offer his pixel-perfect analysis of several known controlled demolitions as comparisons.

Why has he not attempted this? Why in heaven's name would this not be relevant?

For example, if Femr2 could show a typical controlled demolition, and graph the acceleration, and it looked almost identical to the progressive collapse of WTC7, then his data would be very relevant to proving something.

However, most of us will quickly realize that he will never find any such CD to match WTC7, and surely he must realize this as well. One therefore becomes skeptical that his inquiry is actually an honest attempt to determine the facts, as they relate to controlled demolition theories of 9/11 Truth. (remember, that's the point of this forum)
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:46 PM   #210
carlitos
"más divertido"
 
carlitos's Avatar
 
Join Date: Jul 2009
Posts: 18,112
Just to be fair, tfk started the thread here, not femr2.
carlitos is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:47 PM   #211
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
Originally Posted by femr2 View Post
What user ?


You have indicated you are a member at the911forum. Why have you not raised your opinion on this topic there ?
Why will you not show how your discussion is even vaguely relevant to 9/11 Conspiracy theories? Seems a lot more important than what my username is on another forum. I'm just sayin'
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:49 PM   #212
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
Originally Posted by carlitos View Post
Just to be fair, tfk started the thread here, not femr2.
Yup and I made the same comment to him. ETA And I believe he already apologized for the pixel-geek discussion

Femr2 is questioning the relevance of our input and observations, it seems only fair to raise the question of this thread's relevance to conspiracy once again.
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'

Last edited by alienentity; 27th August 2010 at 01:50 PM.
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:53 PM   #213
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by pgimeno View Post
Data is data. It can be used by both sides of the discussion.
Agreed.

Originally Posted by alienentity
offer his pixel-perfect analysis of several known controlled demolitions as comparisons
No problem doing so, for any video, once the techniques have been discussed to everyones satisfaction.

Quote:
and graph the acceleration
Acceleration is pretty trivial to the uses of tracing techniques. Please read the thread, and you will find examples of other metrics it has/will be used to determine.

Quote:
what my username is on another forum
I am femr2 both here and there. Is there any reason to not say what your username on the911forum is ?

Quote:
Femr2 is questioning the relevance of our input and observations
Regardless of where it is located, you should all adhere to the wishes of the OP, and refrain from non-technical discussion. Only polite.

Last edited by femr2; 27th August 2010 at 01:55 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 01:56 PM   #214
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Tom,

A quick summary of recent posts (cutting through the background noise)...


Consider a single white pixel feature on a black background.

If that feature moves left by one pixel, gradually, the aliasing end result is that the intensity of the original pixel drops, and the intensity of the adjacent pixel increases.

Assuming simple 8-bit greyscale colour depth, that alone allows for theoretical detection of 255 positions, translating to 1/255th of a pixel (0.0039 pixel accuracy if you will).

Ramp this up with...

a) Full 24bit RGB colour (3 planes of 8 bit data)
b) Region based pattern matching (normally involving well over 64 separate pixels. Hundreds in the case of static point traces)
c) *8 upscaling
d) LancZos3 filtering

...and I hope you can appreciate that theoretical sub-pixel position change determination accuracy can be...pretty awesome.


Additional static point trace data without dejitter...
Download


New blob test variance results...



Shows the error across pixel boundaries (which makes sense), and the *drift* given circular movement (which is slightly surprising, but about a third of the pixel boundary scale, so may also make sense). Also shows variation in the oscillating frequency dependant upon rotation angle (which makes sense), and flattened, non-oscillating regions at 180 degree intervals (which again makes sense).

Behaviour for square and linear movement is very similar to that of circular movement.

So, from simple observation of the variance graph, I would suggest...

a) The highest accuracy is attained when movement in parallel to the axis being traced.
b) The highest accuracy is maintained when on-axis movement is < 1/4 perpendicular-to-axis movement. < 1/4 gradient. Within this margin for the example equates to within +/- 0.01 pixel accuracy.
c) The highest *drift* is attained when movement is at maximum velocity.
d) *drift* is recovered when velocity reduces.
e) On such small regions (49 pixels) inter-pixel transitions can result in oscillating positional error of ~0.06 pixels.
f) Pixel transition error oscillation period is obviously related to movement velocity.
g) Error does not appear to favour an axis.
h) For near on-axis movement, for a 7*7 region, minimum positional error lies within +/- 0.005 pixels.
i) Interestin'


Thought it would be useful to test a trace of a box corner in perfect freefall...

It's nearish the same scale as the Dan Rather drop distance (both fields). Sample rate is 59.94fps in relative terms.


The x position of the test does not change at all, so the variance is purely SE *noise*...


Previous observations seems to hold true...

a) Vertical variance of around 0.06 pixels.
b) Variance narrows around frame 350, which I imagine is due to the velocity, and so inter-pixel state harmonics.
c) Vertical variance oscillation rate increases as velocity increases, as expected.
d) Drift shifts *downwards* as velocity increases. Will have to double-check if that is a leading or trailing shift, as it will either increase or decrease apparent velocity.
e) Horizontal variance is pure *noise*. +/- 0.001 pixels. No obvious pattern.



Vertical variance of around 0.06 pixels.

This seems to be fairly constant in numerous test conditions.

I'll hazard a guess at a reason...

It's clearly linked to pixel transition, as can be seen by it's oscillatory nature, and that frequency increases with velocity.

Assuming a base hpix (half-pixel) start point, it is also of note that *8 upscaling is applied to the trace region.

0.5/8 = 0.0625

It's conjecture, but it does seem possible that the blending between two pixels can cause cyclic lagging which would be related to upscale multiplier.

It's not a baseless assertion, and it's useful to see how upscaled pixel transitions actually look before dismissing the suggestion. Here's an animated GIF to (hopefully) illustrate the point.




As suggested by W.D.Clinger, a look at the data with multiple graphs based on sample interval.



The image alternates between fields.

Each image includes three graphs, each with a 3 sample interval.

Shows the clear difference between field traces, and as each interval graph is very consistent, shows why I trace each field separately.

Vertical shift between fields is as expected, roughly half pixel.

Shows a few jumps on one of the fields (which is not the fault of SynthEyes, but video quality).

I'll sort out the velocity and acceleration derived views later.

Will be wanting to move over to the better quality Cam#3 footage pretty soon, but happy to respond to technical quesries beforehand.

DeJitter processing has been deliberately very simple to date, to make released spreadsheet data simple, but may begin using more advanced techniques. No complaints about more complex spreadsheet data once I do though please.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 02:46 PM   #215
jaydeehess
Penultimate Amazing
 
jaydeehess's Avatar
 
Join Date: Nov 2006
Location: 40 miles north of the border
Posts: 20,821
Here's the thing, and I have stated it before in this and related threads;
it really does not matter if femr manages to get a precise plot of the velocity of several points on the structure other than to say "NIST should have done all this too". NIST was not concerned, nor would there be any reason to be, with the minutia of the final moments of collapse. Determing , to an exacting degree(if possible) the precise behaviour of this structure, approx 15 seconds into its collapse that took just under 17 seconds in total is never going to allow anyone to determine what caused the collapse.(which began 15 seconds prior to this much dissected few moments)

YES, once the last phase of collapse began it went rather fast. No doubt about it but that does not constitute any evidence of nefarious mis-doings.
jaydeehess is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 05:04 PM   #216
tsig
a carbon based life-form
 
Join Date: Nov 2005
Posts: 39,049
Originally Posted by femr2 View Post
Tom,

Additional static point trace data without dejitter...

Download
At the end of the day all you have is "looks like".
tsig is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 06:28 PM   #217
pgimeno
Illuminator
 
pgimeno's Avatar
 
Join Date: Feb 2009
Location: Spain
Posts: 3,324
Originally Posted by tfk View Post
I'd like to request that everyone (including me) keep this thread to the engineering. There are plenty of other places that we can express our dissatisfaction with each of our perceptions of the other side's politics, agendas, etc.

Here, let's stick to engineering, please.
Bump from the OP.
__________________
Ask questions. Demand answers. But be prepared to accept the answers, or don't ask questions in the first place.
pgimeno is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 08:15 PM   #218
beachnut
Penultimate Amazing
 
beachnut's Avatar
 
Join Date: Oct 2006
Location: Dog House
Posts: 24,962
The collapse of WTC 7 starts with internal collapse. Does the tracking work on the deformation in the building facade to give some insight into the massive internal failures.

The collapse of WTC 7 was in motion internally for many seconds prior to the facade falling. Except the penthouse fell into the WTC 7 due to interior failures. What does the tracking of the penthouse reveal? Was the acceleration of the penthouse indicative of massive internal failure, or slower and some sort of incremental failure; and which would match the NIST model of collapse.

Since there were no explosives or thermite used on 911 to destroy the WTC complex; will this tracking give a signature for gravity collapse vs CD; or is the fact gravity is the primary energy source for CD and gravity collapse would that be impossible?

Are you going to analyze the penthouse collapse, or ignore the entire collapse?

Last edited by beachnut; 27th August 2010 at 08:16 PM. Reason: engineer i b
beachnut is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 09:22 PM   #219
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by beachnut View Post
Does the tracking work on the deformation in the building facade to give some insight into the massive internal failures.
It will be possible to suggest probable internal behaviours from analysis of such low level external feature positional change data, yes.

Quote:
WTC 7 was in motion internally for many seconds prior to the facade falling.
Access to the 7 minute Cam#3 footage NIST have would be very handy.

Quote:
What does the tracking of the penthouse reveal?
Until the techniques are accepted, it is not appropriate to begin making conclusions. Basic raw trace data for the East Penthouse descent is contained within the Cam#3 dataset if you wish to analyse it.

Quote:
Was the acceleration of the penthouse indicative of massive internal failure, or slower and some sort of incremental failure; and which would match the NIST model of collapse.
Until the techniques have been accepted, and scaling metrics agreed, ...

I'm not avoiding the question, it's fine and valid. But until there can be acceptance that traces can be performed with positional accuracy (x), derived acceleration accuracy (y) and scaling metric accuracy (z), it is not time to state results.

Quote:
Are you going to analyze the penthouse
Yes. Again, some data is already there if you choose to jump ahead.

An easier way to progress is...

Do you accept the validity of the tracing techniques to determine accurate metrics on specified building feature movements ?

If so, what levels of accuracy are you prepared to accept for...

a) position error, in pixels
b) scaling metric error, in pixels/ft (footage dependant)
c) velocity error, in ft/s (footage dependant)
d) acceleration error, in ft/s^2 (footage dependant)

I do not actually expect you to be able to answer these questions at this point.

There is work to be done first.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 09:45 PM   #220
tsig
a carbon based life-form
 
Join Date: Nov 2005
Posts: 39,049
Originally Posted by femr2 View Post
It will be possible to suggest probable internal behaviours from analysis of such low level external feature positional change data, yes.


Access to the 7 minute Cam#3 footage NIST have would be very handy.


Until the techniques are accepted, it is not appropriate to begin making conclusions. Basic raw trace data for the East Penthouse descent is contained within the Cam#3 dataset if you wish to analyse it.


Until the techniques have been accepted, and scaling metrics agreed, ...

I'm not avoiding the question, it's fine and valid. But until there can be acceptance that traces can be performed with positional accuracy (x), derived acceleration accuracy (y) and scaling metric accuracy (z), it is not time to state results.


Yes. Again, some data is already there if you choose to jump ahead.

An easier way to progress is...

Do you accept the validity of the tracing techniques to determine accurate metrics on specified building feature movements ?

If so, what levels of accuracy are you prepared to accept for...

a) position error, in pixels
b) scaling metric error, in pixels/ft (footage dependant)
c) velocity error, in ft/s (footage dependant)
d) acceleration error, in ft/s^2 (footage dependant)

I do not actually expect you to be able to answer these questions at this point.

There is work to be done first.
Great! Get to it.
tsig is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 10:21 PM   #221
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
Originally Posted by femr2 View Post
Until the techniques are accepted, it is not appropriate to begin making conclusions.

Until the techniques have been accepted, and scaling metrics agreed, ...

I But until there can be acceptance that traces can be performed with positional accuracy (x), derived acceleration accuracy (y) and scaling metric accuracy (z), it is not time to state results.
.
But haven't y'all been making conclusions about WTC1 already, as outlined by Captain Tom's 'OOS collapse propagation model' and the '
Re: Missing Jolts found ???; film at 11' threads?

I think you ought to just state your case for the accuracy of your measurements, give your calculations for error, and be done with it. People can either accept your methods or reject them, based on their own perceptions and expertise.

It seems a bit late for you to be pulling back all your conclusions at this point.
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 27th August 2010, 10:23 PM   #222
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
'a) position error, in pixels
b) scaling metric error, in pixels/ft (footage dependant)
c) velocity error, in ft/s (footage dependant)
d) acceleration error, in ft/s^2 (footage dependant)'

Again, go ahead and give those estimates for your data.
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 06:05 AM   #223
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by alienentity View Post
But haven't y'all been making conclusions about WTC1 already, as outlined by Captain Tom's 'OOS collapse propagation model' and the '
Re: Missing Jolts found ???; film at 11' threads?
Indeed. Perhaps I should have said...

Until the techniques are accepted, it is not appropriate to begin making conclusions here.

The current situation has arisen due to certain folk, tfk in particular, disputing the accuracy attainable through the tracing methods employed.

The trigger for this entire thread was my suggested positional accuracy of +/- 0.2 pixels for the Dan Rather footage, which tfk disputed, and still does.

The discussion is ongoing, with me providing more and more detail about the methods, folk delving into lower and lower scale sources of noise and distortion, and very few folk announcing...okay I'm happy that your tracing methods have been suitably explained and are accurate to (x) precision.

Whilst it's been made perfectly clear that the methods have been used extensively for WTC 1, that is not the case for WTC 7, and so, as I have been doing *this*, I have not really begun the process of analysing WTC 7 trace data.

The conclusions drawn from trace data usage can be quite complex, and so it is necessry for such methods to be understood, and accepted. Otherwise it is too easy for those skeptical of the proposed conclusions to simply dismiss such by blaming what they perceive to be invalid methods (ie sub-pixel accurate feature movement trace data analysis).

Quote:
I think you ought to just state your case for the accuracy of your measurements, give your calculations for error, and be done with it. People can either accept your methods or reject them, based on their own perceptions and expertise.
As far as I'm concerned, I have. It is the fact that others will disagree, but then do not provide alternate accuracy details or reasoning, that's the problem. I do not want anyone to have any justifiable reason to *reject* them.

Quote:
It seems a bit late for you to be pulling back all your conclusions at this point.
I'm not. I'm simply saying that I want to progress to general acceptance of the methods and accuracy before presenting conclusions here.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 07:41 AM   #224
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by alienentity View Post
Go ahead and give those estimates for your data.
a) position error, in pixels

Dan Rather footage - +/- 0.2 pixels

b) scaling metric error, in pixels/ft (footage dependant)

+/- 1 pixel

For WTC 7 there is limited building measurement data available, so with the caveat of accepting the scant NIST provided values...

Vertical scaling metric 3.41 to 3.47 ft/pixel
Horizontal scaling metric 1.64 to 1.66 ft/pixel

Note that these are global metrics over the full distance, and do not affect the positional error metric.

Scaling Metrics for the Cam#3 footage are of higher accuracy, as the footage is of higher quality and resolution (which is why I stated to tfk at the beginning of our discussion that I'd prefer to use that footage)

c) velocity error, in ft/s (footage dependant)

There has been no agreement of noise reduction or smoothing process. Until there is *some* agreement, it's too early to state.

d) acceleration error, in ft/s^2 (footage dependant)'

There has been no agreement of noise reduction or smoothing process. Until there is *some* agreement, it's too early to state.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 07:55 AM   #225
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Originally Posted by femr2 View Post
Thought I'd pre-empt the inevitable *disbelief* that my response is bound to provoke.

Consider a single white pixel feature on a black background.

If that feature moves left by one pixel, gradually, the aliasing end result is that the intensity of the original pixel drops, and the intensity of the adjacent pixel increases.

Assuming simple 8-bit greyscale colour depth, that alone allows for detection of 255 positions, translating to 1/255th of a pixel (0.0039 pixel accuracy if you will).

Ramp this up with...

a) Full 24bit RGB colour (3 planes of 8 bit data)
b) Region based pattern matching (normally involving well over 64 separate pixels. Hundreds in the case of static point traces)
c) *8 upscaling
d) LancZos3 filtering

...and I hope you can appreciate that potential technical sub-pixel position change determination accuracy can be...awesome
Yeah, sure. And, in principle, my 3rd grade ruler can measure to nanometers, because...

Let's cut to the chase.

There are two types of errors to consider: static errors (how good is SynthEyes at locating some non-moving feature anywhere in the image) and dynamic errors (how good is it at locating a moving feature at a given instant). The dynamic error has nothing to do with SynthEyes, of course, but everything to do with video's usual motion artifacts.

The total error in the reported location of any moving object with respect to any stationary feature is going to be the sum of those two errors. (One static error & one dynamic error.) The lower bound for this error is 2 times the static error.

Your own data doesn't support those levels of precision.

You gave me 3 additional static points. I compared the reproducibility of SynthEyes to locate those static points.

All of those static point should be stationary with respect to each other. The errors associated with the tracking of those static points is a good lower bound for the accuracy of your tracking.

Here's the result:

This chart shows the 4 static points, with the traces artificially displaced by 1 pixel for clarity.





The average position (the "DC" component) variations are due mostly to camera motion. They track each other well in the 4 plots. So those aren't the problems.

The differences in the magnitudes of the alternating part of the curves are a problem. The errors associated with just variations in the tracker picking up the static reference point can be quantified.

The errors associated with these numbers are an accurate reflection of SynthEyes ability to reliably locate a fixed reference point at several places around the image.

Here is the result, comparing the Y locations of each of the three new static points to the original ("Static Y") value.

Note that these values were calculated after doing your "2 point smoothing". (Without this technique, the errors were about 50% higher.)

Note that the second group was calculated after the gross slueing of the camera (that occurred between 3 & 10 seconds) stopped.

 Ref 9/16Ref 11/17Ref 13/15RMS Errors
Errors 0 - 17 sec    
Avg0.100.160.160.14
StDev0.070.090.090.08
Avg + 2 Sigma0.240.330.330.30
Avg + 3 Sigma0.300.420.410.38
     
Errors 10 - 17 sec    
Avg0.150.230.230.20
StDev0.050.060.060.05
Avg + 2 Sigma0.250.340.340.31
Avg + 3 Sigma0.300.390.400.37
.
This is a fair metric of the reproducibility of SynthEyes to track a stationary feature.

The RMS value is just the "mean of the means" of the individual errors and the individual standard deviations.

Note that I could only run these numbers for the Y point, since that's the only info that you provided with your new static points. It might get a little better, or a little worse, once the X values are included.

Now, when I'm justifying my test results to "the customer's in-house representative" (aka, the QA department), if he is in a good mood, he could be persuaded to allow me to claim the "3 sigma RMS value" accuracy (0.37 pixels/location).

If he's in a bad mood, he'll jump right to the worst case 3 sigma value (0.42 pixels/location).

And then it's obvious that you've got that error for each location (the reference point & the tracked roof line point), so the best that I can claim is twice this value (around 0.8 pixels).

This IS the lesson of this sort of data analysis. Errors are a bitch. And they accumulate fast.

I'll be anxious to hear WD's critique.
___

I also exchanged an email with Russ Andersson, the inventor/programmer for SynthEyes. Here are a couple of the questions I asked & his replies:

Originally Posted by tfk
We would like to track locations within video that we've downloaded from archived (pre-2002) TV broadcast video (broadcast in US, NTSC, standard definition, 525 line interlaced). Most of the video is taken from tripod mounted cameras. Some of them are from hand held cameras.
Originally Posted by Russ Andersson
Note that an awful lot of such unintended video will not contain the camera motion needed to determine 3-D parameters.
Also, interlaced video has only half vertical resolution (ie around 240 usable) which makes achieving decent accuracy harder.
.
We would like to be able to track several points within the video better than about 0.5 pixels.
Originally Posted by Russ Andersson
RMS errors in the 0.2-0.4 range are fairly typical on reasonable (solved 3D) shots. Lens distortion and other problems can easily blow this number out.
.

To what extent does the motion & contrast within the video affect the tracking accuracy. For example, some of the videos will be "disaster videos", and there is frequently fire & smoke wafting in front of our desired reference points. Will this likely be a problem?
Originally Posted by Russ Andersson
Certainly you can degrade the imagery in ways that will affect accuracy. This is artist-controlled --- ultimately you are limited by the skill/accuracy/time of your tracking artist.
.

I assume that video compression of the files (before we have access to them) will reduce our precision. Can you direct me to some reference that would help me to begin to quantify what I can expect?
Originally Posted by Russ Andersson
No, sorry. That's not something that normally needs to be quantified explicitly. SynthEyes is a visual effects tool, not a surveying tool.

tom

Last edited by tfk; 28th August 2010 at 08:17 AM.
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 08:54 AM   #226
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
PS. Sudden thought...

But the accuracy above might be significantly improved with improved (better than 2 point average) filtering.

We'll see...

tom
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 09:19 AM   #227
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
PS. Sudden thought...

But the accuracy above might be significantly improved with improved (better than 2 point average) filtering.

We'll see...

tom
Indeed. Must point out that the 2 point moving average is simply the simplest, most primitive, way to reduce the deinterlace jitter.

Better methods are definitely available, such as shifting one field dataset up by half a pixel, or shifting both towards each other by a quarter pixel. All measurements are relative to a start point, so the shifting of data is valid.

If you are considering looking at the effect on accuracy of smoothing, it should be in a 2 step process....treat interlace jitter, then smooth.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 09:51 AM   #228
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Originally Posted by femr2 View Post
Indeed. Must point out that the 2 point moving average is simply the simplest, most primitive, way to reduce the deinterlace jitter.

Better methods are definitely available, such as shifting one field dataset up by half a pixel, or shifting both towards each other by a quarter pixel. All measurements are relative to a start point, so the shifting of data is valid.

If you are considering looking at the effect on accuracy of smoothing, it should be in a 2 step process....treat interlace jitter, then smooth.
1. The deinterlace jitter is not the only source of error. It is not the predominant one in two of the traces.

2. The "smoothing algorithm" (2 point average) that I used for the results above is exactly the one on which you based your previous results. Denigrating it at this point doesn't help your case.

3. You might consider addressing the principle (setting aside for a moment the numbers) pointed out in that long post.

Which is: "Your error in the reported position of a moving feature can not be less than twice the error in your ability to calculate static points."


tom

Last edited by tfk; 28th August 2010 at 09:52 AM.
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 09:59 AM   #229
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
femr,

You've expressed a strange (to my way of thinking) interest in the "maximum possible resolution of SynthEyes". This is irrelevant. The important question is "what is the MINIMUM resolution that I can prove?"

For that matter, I am not interested at all in the theoretical performance of SE, per se. My interest is ONLY as it relates to its ability to determine position vs. time for the collapse times.

As far as I am concerned, the "blob tests" are irrelevant to the question that I find pertinent, because they ignore all the myriad errors that real optics & real video can introduce into your data. Someone else may be interested in them. I skip them.

Originally Posted by femr2 View Post
It will be possible to suggest probable internal behaviours from analysis of such low level external feature positional change data, yes.
I find this to be a VERY bold statement.

I'd find it bold coming from a structural engineer. But, of course, I'd listen carefully to his explanations.

Originally Posted by beachnut
WTC 7 was in motion internally for many seconds prior to the facade falling.
Originally Posted by femr2 View Post
Access to the 7 minute Cam#3 footage NIST have would be very handy.
Why do you do this: intentionally misrepresent, and then evade, comments? Beach is clearly talking about the several seconds prior to the start of the facade falling. You HAVE that video data. NIST has not withheld it.

You could have addressed his comment directly, instead of a less-than-brilliant attempt at NIST-slapping.


tom

PS. I'm just catching up over brunch. I've got a ton of work in the next 5 days. I'll be MIA for a bit.
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 11:02 AM   #230
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
You've expressed a strange (to my way of thinking) interest in the "maximum possible resolution of SynthEyes". This is irrelevant.
The reason for performing the SE tests is in part due to you suggesting that the SE algorithms were responsible for some of the dataset noise.

In addition, performing the tests has allowed better understanding of where, and of what magnitude, tracing mechanics noise actually arises, namely the identified ~0.0625 pixel variance due to pixel transitions, velocity related *drift* probably due to harmonics in pixel state transition, etc... SE *noise* itself has been shown to be in the 0.001 pixel range.

Quantifying these metrics allows clearer understanding of noise source, and may also allow for more advanced noise reduction to be applied to post-processing the datasets.

Understanding that velocity has a slight effect, and that the 0.0625 pixel variance is transition related is very useful.

Quote:
The important question is "what is the MINIMUM resolution that I can prove?"
That's fine, but I will highlight that the position variance over 13s of the Dan Rather data, sampled at 59.94Hz, and with no non-jitter based smoothing remains within ~+/- 0.2 pixels.

It is not valid to add static point variance to position variance, as the entire point of static point tracing is to determine camera shake. How would you propose separating static point trace *noise* from valid camera movement ?

Quote:
For that matter, I am not interested at all in the theoretical performance of SE, per se. My interest is ONLY as it relates to its ability to determine position vs. time for the collapse times.
Fine, though it must be made very clear that all of the metrics you are looking at relate to the Dan Rather viewpoint video, not *position vs. time for the collapse times*. All of the error ranges change when using the Cam#3 footage for instance.

Quote:
As far as I am concerned, the "blob tests" are irrelevant to the question that I find pertinent, because they ignore all the myriad errors that real optics & real video can introduce into your data. Someone else may be interested in them. I skip them.
That's your perogative. However, I think it is safe to say that I have proved that SE is more than capable of determining sub-pixel feature position, and indeed quantified to what level it is capable of doing so. I assume there will be no further suggestion that sub-pixel feature position change determination cannot be performed accurately.

A primary reason for performing the blob tests is to prove what level of error is introduced by the tracing mechanism, and which is caused by other noise sources.

Again, all error range data being discussed applies only to the Dan Rather video instance.

Happy with 0.0625 pixel variance due to tracing mechanism behaviours ?

Quote:
I find this to be a VERY bold statement.
We'll see The data for vertical propogation (bottom to top) is quite interesting, but later...

Quote:
Why do you do this: intentionally misrepresent, and then evade, comments?
It's not an evasion in the slightest. That is your pre-determined viewpoint coming out. The reason I'd like the full length Cam#3 footage is that building movement is ocurring from the very start of my copy, and, from the low resolution graphs provided by NIST, it's clear that movement began much earlier. I'd like to see it.

The Cam#3 data shows early movement. It's ridiculous to suggest I'm evading such.

Quote:
You could have addressed his comment directly, instead of a less-than-brilliant attempt at NIST-slapping.
Quite how you make up that interpretation is beyond me.

Oh, and whilst we're there...you know the *kink* ? NIST treated it as vertical movement. It's not. It's primarily due to the pre-descent flexing, and is not vertical in nature, but rather north/south, but, again, later...

(My previous paragraph is NIST slapping.)

Last edited by femr2; 28th August 2010 at 12:54 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 11:06 AM   #231
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
1. The deinterlace jitter is not the only source of error. It is not the predominant one in two of the traces.
How have you separated camera movement from noise ?

Quote:
2. The "smoothing algorithm" (2 point average) that I used for the results above is exactly the one on which you based your previous results. Denigrating it at this point doesn't help your case.
I've said from day one that the dejitter process was deliberately simple. There's nothing negative about using a better process at all. Surprised no-one has mentioned it before. There are numerous ways of dealing with it. Reasoning for keeping it simple has already been stated.

Quote:
3. You might consider addressing the principle (setting aside for a moment the numbers) pointed out in that long post.

Which is: "Your error in the reported position of a moving feature can not be less than twice the error in your ability to calculate static points."
Again, how have you separated camera movement from noise ?


And...


I thought we all understood and accepted that there was noise in the data.

What would have been more useful for me personally is all manner of input on various different viewpoint on treating that noise.

If you choose to focus on *how bad can we make it*, rather than *how good can we make it*, that's fine.

I'll be applying more of my time to testing smoothing techniques than the former.

Last edited by femr2; 28th August 2010 at 11:10 AM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 12:45 PM   #232
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
There are two types of errors to consider: static errors (how good is SynthEyes at locating some non-moving feature anywhere in the image) and dynamic errors (how good is it at locating a moving feature at a given instant). The dynamic error has nothing to do with SynthEyes, of course, but everything to do with video's usual motion artifacts.
Agreed, though that's one reason why I've performed the blob tests, to get an idea of the effect of underlying motion error (0.0625 pixel mechanical variance + velocity slew)

Also must reiterate that static point traces are done to detect camera movement, and there's no perfect way of separating camera movement from noise in those traces. Can be estimated, sure, but that involves using all of the available smoothing and noise reduction processes. (Averaging multiple static points is also useful of course)

Quote:
The total error in the reported location of any moving object with respect to any stationary feature is going to be the sum of those two errors. (One static error & one dynamic error.) The lower bound for this error is 2 times the static error.
Yes, but it's how the static feature error is determined that complicates that.

Quote:
The errors associated with the tracking of those static points is a good lower bound for the accuracy of your tracking.
For the footage being used, sure. I'd focus on differences between each static point trace.

Quote:
This chart shows the 4 static points, with the traces artificially displaced by 1 pixel for clarity.
I assume that without jitter treatment.

Quote:
The differences in the magnitudes of the alternating part of the curves are a problem.
Could be due to variable distance from camera.

Quote:
The errors associated with just variations in the tracker picking up the static reference point can be quantified.
Fine.

Quote:
The errors associated with these numbers are an accurate reflection of SynthEyes ability to reliably locate a fixed reference point at several places around the image.
Fine.

Quote:
Here is the result, comparing the Y locations of each of the three new static points to the original ("Static Y") value.
Happens to be the the one with most variance, and the largest general offset. I'd have thrown that trace away and used some new ones. Looking at all four static point traces overlaid shows me that the initial one might need looking at, or rejecting. I have no problem doing MORE additional static point traces


Quote:
And then it's obvious that you've got that error for each location (the reference point & the tracked roof line point), so the best that I can claim is twice this value (around 0.8 pixels).

This IS the lesson of this sort of data analysis. Errors are a bitch. And they accumulate fast.
Unsmoothed variance over 13 seconds of the NW corner trace is around +/- 0.2 pixels. How would you explain this ? SE managed to get it at half your estimate 60 times a second for over 10 seconds.

Quote:
I'll be anxious to hear WD's critique.
Me too.

Last edited by femr2; 28th August 2010 at 01:11 PM.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 12:46 PM   #233
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
femr,

Originally Posted by femr2 View Post
How have you separated camera movement from noise ?
All the static points were subject to the same camera movement.

The difference in their reported (by SE) location is the error (not just "noise") in SE's tracking ability of static features.

In other words, camera motion is automatically eliminated from this analysis.

Originally Posted by femr2 View Post
Again, how have you separated camera movement from noise ?
See above.

Originally Posted by femr2 View Post
I thought we all understood and accepted that there was noise in the data.
True. Doesn't change anything I've said.

Originally Posted by femr2 View Post
What would have been more useful for me personally is all manner of input on various different viewpoint on treating that noise.
Again, "noise" is only one component of error. There are others.

There comes a point where you run out of options in "treating" (i.e., reducing) error, and are left saying "this is the limit of accuracy of my equipment, data & analysis".

Every experiment reaches this point.

Originally Posted by femr2 View Post
If you choose to focus on *how bad can we make it*, rather than *how good can we make it*, that's fine.
Wow. Read what I said again. You're misstating.

This statement does not demonstrate a fluency with the fundamentals of experimental technique or analysis.

Originally Posted by femr2 View Post
I'll be applying more of my time to testing smoothing techniques than the former.
Fine.


ETA [delete]

tom

Last edited by tfk; 28th August 2010 at 12:48 PM.
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 01:16 PM   #234
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
All the static points were subject to the same camera movement.
Agreed.

Quote:
The difference in their reported (by SE) location is the error (not just "noise") in SE's tracking ability of static features.
Pretty much.

Quote:
In other words, camera motion is automatically eliminated from this analysis.
Please explain.

Quote:
There comes a point where you run out of options in "treating" (i.e., reducing) error, and are left saying "this is the limit of accuracy of my equipment, data & analysis".
Absolutely.

Quote:
Wow. Read what I said again. You're misstating.
It's just that position variance is roughly +/- 0.2 pixels, and your suggested error is 0.8 pixels.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 01:29 PM   #235
alienentity
Illuminator
 
alienentity's Avatar
 
Join Date: Feb 2009
Posts: 4,325
tfk wrote 'I assume that video compression of the files (before we have access to them) will reduce our precision. Can you direct me to some reference that would help me to begin to quantify what I can expect?'
Russ Andersson replied
'No, sorry. That's not something that normally needs to be quantified explicitly. SynthEyes is a visual effects tool, not a surveying tool.'

What does he mean?
__________________
Heiwa - 'Anyone suggesting that part C structure can one-way crush down part A structure is complicit to mass murder!'
000063 - 'Problem with the Truthers' theories is that anyone with enough power to pull it off doesn't need to in the first place.'
mrkinnies 'I'm not a no-planer' 'I don't believe Flight 77 hit the Pentagon'
alienentity is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 01:46 PM   #236
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
femr,

Originally Posted by femr2 View Post
Agreed, though that's one reason why I've performed the blob tests, to get an idea of the effect of underlying motion error (0.0625 pixel mechanical variance + velocity slew)
We use the work "mechanical" in completely different meanings...

"... underlying motion errors ..." ?

I've read some of your blob test stuff. It

Originally Posted by femr2 View Post
Also must reiterate that static point traces are done to detect camera movement, and there's no perfect way of separating camera movement from noise in those traces. Can be estimated, sure, but that involves using all of the available smoothing and noise reduction processes. (Averaging multiple static points is also useful of course)
All the static points were subject to identical camera motion. This eliminates camera motion from being a source of error in this analysis.

That's also why I provided a 2nd data set for when the camera settled down.

It was simple to get the statistics for the 3-10 second interval. (Looking at the "Static X" values, you can see that this is the period where the

The average static errors turn out to be actually less while the camera is moving. While it is a significant percent difference, this may be just chance.

 Ref 9/16Ref 11/17Ref 13/15RMS Errors
Errors 0 - 17 sec    
Avg0.100.160.160.14
StDev0.070.090.090.08
Avg+2 Sigma0.240.330.330.30
Avg+3 Sigma0.300.420.410.38
Errors 10 - 17 sec    
Avg0.150.230.230.20
StDev0.050.060.060.05
Avg+2 Sigma0.250.340.340.31
Avg+3 Sigma0.300.390.400.37
Errors 3 - 10 seconds    
Avg0.080.150.130.12
StDev0.050.050.060.05
Avg+2 Sigma0.190.250.240.23
Avg+3 Sigma0.240.310.300.29


Originally Posted by femr2 View Post
Originally Posted by tfk
The errors associated with the tracking of those static points is a good lower bound for the accuracy of your tracking.
For the footage being used, sure. I'd focus on differences between each static point trace.
That's exactly what I'm posting: the differences between the static points.

Originally Posted by femr2 View Post
I assume that without jitter treatment.
The graph: yes, without jitter treatment.

The spreadsheet calculations that I've tabulated here:

As I said before, I posted the "with 2 point averaging" results.

I calculated the "without 2 point averaging" results too. Those errors are about 50% higher.

Originally Posted by femr2 View Post
Originally Posted by tfk
The differences in the magnitudes of the alternating part of the curves are a problem.
Could be due to variable distance from camera.
Nope. Because the differences are insignificant to begin with. They are all - optically - at the same distance: infinity. And those distances don't change one iota over the course of the video, but the DIFFERENCES between reported locations does change.

Originally Posted by femr2 View Post
Originally Posted by tfk
Here is the result, comparing the Y locations of each of the three new static points to the original ("Static Y") value.
Happens to be the the one with most variance, and the largest general offset. I'd have thrown that trace away and used some new ones. Looking at all four static point traces overlaid shows me that the initial one might need looking at, or rejecting. I have no problem doing MORE additional static point traces
Nope. The "Static Y" tracing is the most stable of the 4. Look at the purple curve in my post 225 above.

[quote=femr2;6275512]
Unsmoothed variance over 13 seconds of the NW corner trace is around +/- 0.2 pixels. How would you explain this ? SE managed to get it at half your estimate 60 times a second for over 60 seconds.

All kinds of possible explanations. All (for the moment) irrelevant.

Question for you: how do you explain these variations in stationary point info in the data if SE can determine positions with the accuracies that you've claimed?

___

A point that is pertinent: If you want to post the Y data associated with the 3 new static points, I'll be able to see if that improves or degrades the accuracy. I'll also be able to give you a metric for the rotation of the image.

AND (bonus) accurate distance calculations (not just x & y values) for the roof feature drop locations from each static point.

This will take a bit. Again, way busy for the next several days.


tom
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 01:53 PM   #237
tfk
Illuminator
 
Join Date: Oct 2006
Posts: 3,454
Originally Posted by alienentity View Post
tfk wrote 'I assume that video compression of the files (before we have access to them) will reduce our precision. Can you direct me to some reference that would help me to begin to quantify what I can expect?'
Russ Andersson replied
'No, sorry. That's not something that normally needs to be quantified explicitly. SynthEyes is a visual effects tool, not a surveying tool.'

What does he mean?
My suspicion is that he means "I run a small business. Surveying is not my market, and I don't have the time to spend going into detail that is irrelevant to my business. And any statement I make regarding its absolute accuracy could come back to bite me in the butt. "

I think his program, if properly used, has the potential to do "surveying".

The two points that he made that caught my eye were:

1. "Need the 3D camera to object location info to solve really accurately."
2. "Accuracy depends on the diligence of the operator."

We don't have the 3D camera info.
femr has said that his analysis are done with none of his intervention.


tom
tfk is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 02:10 PM   #238
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
The two points that he made that caught my eye were:

1. "Need the 3D camera to object location info to solve really accurately."
2. "Accuracy depends on the diligence of the operator."

We don't have the 3D camera info.
I have the camera location kicking around somewhere in my piling system, but I assume you are aware of the three dimensional scene *solving* algorithms of SynthEyes ? (Determines 3D position ofver time by solving multiple 2D positional data changes)

Quote:
femr has said that his analysis traces are done with none of his intervention.
Absolutely. Zero intervention.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 02:25 PM   #239
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
Originally Posted by tfk View Post
We use the work "mechanical" in completely different meanings...

"... underlying motion errors ..." ?
As long as we're talking about error that is solely the fault of SE, lets call it SE-error.

Quote:
I've read some of your blob test stuff. It
Gonna leave me hanging ?

Quote:
percent difference
Percent ? Please elaborate.

Quote:
That's exactly what I'm posting: the differences between the static points.
Okay.

Quote:
Nope. Because the differences are insignificant to begin with. They are all - optically - at the same distance: infinity. And those distances don't change one iota over the course of the video, but the DIFFERENCES between reported locations does change.
I may need to recheck for trace lock issues. Will take a while.

Quote:
Nope. The "Static Y" tracing is the most stable of the 4. Look at the purple curve in my post 225 above.
I'm pretty sure that trace is dejittered.

What I was saying though, is that if you remove the offsets, then that trace has a noticable offset of it's own, which will skew your results.

Quote:
All kinds of possible explanations. All (for the moment) irrelevant.
I'll ask again later then.

Quote:
Question for you: how do you explain these variations in stationary point info in the data if SE can determine positions with the accuracies that you've claimed?
Video quality and camera movement.
Video quality encompasses lots of noise sources, such as compression artefacts, CCD artefacts, lens distortion, atmospheric distortion, focus, resolution, interlace jitter, ...

Quote:
A point that is pertinent: If you want to post the Y X data associated with the 3 new static points, I'll be able to see if that improves or degrades the accuracy. I'll also be able to give you a metric for the rotation of the image.
Okay. I guess you'll want the region center-points too then

Quote:
AND (bonus) accurate distance calculations (not just x & y values) for the roof feature drop locations from each static point.
Ah. If you're okay with them using the same scaling metric as used for WTC 7, no problem. Otherwise it means a whole load of faffing about.
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 28th August 2010, 04:40 PM   #240
femr2
Illuminator
 
Join Date: Apr 2009
Posts: 3,859
A hack at static point trace variance...



I've applied some processing to the data.

1) Aligned separate traces by either +0.1 or -0.1 pixels relative to t9/16
2) Normal 2 point moving average for jitter treatment.
3) Average of all four traces taken as root.
4) Variance as subtraction of each trace from root.
5) 7 point moving average on variance data (just to simplify the display).

Am sure there will be opinion
femr2 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Conspiracies and Conspiracy Theories » 9/11 Conspiracy Theories

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 10:00 PM.
Powered by vBulletin. Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.