I think I can grasp the gist of that complex beastie, yes.
Am hoping to identify *plumbness* changes to sub-pixel level, so should hopefully be able to determine anything more than 0.02 degrees (assuming photos similar to those of WTC 1 above).
Are you okay with the concept of "more than" ?
I think it's safe to assume that when you state less than 0.5/1, that you mean more than 0.02, but who knows ? I think you just like an argument, even if it's with your own shadow.
So, more than 0.02 degrees ?
femr,
Excellent.
1. Easy
Perhaps you could tell us the name of, or explain (if it's original), the algorithm you're using for your sub-pixel edge technique.
2. Easy
Perhaps you could show us examples of your raw images, blown up to, say 20 - 50 pixel wide strips capturing the actual edges at several points along its vertical dimension.
3. Tougher
Perhaps you could demonstrate your sub pixel technique in operation with real WTC data.
4. Tougher yet
Perhaps you could create a standardized blind (or better, double blind) test where you can prove that your technique works with known edge angles and spatial frequencies.
Create sharp lines of a certain angle. Use a diffusion filter of various blurring radius. Then reverse the process with your technique & record filter passes vs. angular error.
Perfectly fine.
Absolutely NOT OK.
I win 90% of my arguments with my shadow. I OWN him.
That is yours to prove.
Tom
Excellent.
1. Easy
Perhaps you could tell us the name of, or explain (if it's original), the algorithm you're using for your sub-pixel edge technique.
2. Easy
Perhaps you could show us examples of your raw images, blown up to, say 20 - 50 pixel wide strips capturing the actual edges at several points along its vertical dimension.
3. Tougher
Perhaps you could demonstrate your sub pixel technique in operation with real WTC data.
4. Tougher yet
Perhaps you could create a standardized blind (or better, double blind) test where you can prove that your technique works with known edge angles and spatial frequencies.
Create sharp lines of a certain angle. Use a diffusion filter of various blurring radius. Then reverse the process with your technique & record filter passes vs. angular error.
Perfectly fine.
Absolutely NOT OK.
I win 90% of my arguments with my shadow. I OWN him.
That is yours to prove.
Tom
Tom,
Give it a rest. Find me some super-duper quality images, and I'll try and find some tilt. I'm really not interested in engaging in yet more of your infinite desire to *prove* any technique that's not yours, done by a structural engineer who happens to be a specialist in sub-pixel (non)linear feature detection or simply done by a *twoofer* to be worthless.
If I find something of interest I'll obviously include whatever techniques were used at the time, and then you can complain as much as you like.
For a laugh, can you grasp the complete concept of the words "hoping" and "hopefully" ? The suggested 0.02 degree figure is for a >1 pixel change of the included WTC 1 image, using a rough translation into real-word distance units and viewpoint translation to determine an associated angle. Very rough. Hopefully some mondo images will turn up and I can have a bash at 'em.
As I said very early in this thread, I'm after images. If you haven't got any, there's nothing to see here.
Give it a rest. Find me some super-duper quality images, and I'll try and find some tilt. I'm really not interested in engaging in yet more of your infinite desire to *prove* any technique that's not yours, done by a structural engineer who happens to be a specialist in sub-pixel (non)linear feature detection or simply done by a *twoofer* to be worthless.
If I find something of interest I'll obviously include whatever techniques were used at the time, and then you can complain as much as you like.
For a laugh, can you grasp the complete concept of the words "hoping" and "hopefully" ? The suggested 0.02 degree figure is for a >1 pixel change of the included WTC 1 image, using a rough translation into real-word distance units and viewpoint translation to determine an associated angle. Very rough. Hopefully some mondo images will turn up and I can have a bash at 'em.
As I said very early in this thread, I'm after images. If you haven't got any, there's nothing to see here.
OK. I guess I was looking for the next level of "why" when I asked.
You want to know whether there was any progressive tilt - why?
You want to know how much - why?
You want to confirm (via video analysis) the progressive tilt - why?
Really, why? I'm not trying to be a jerk; how did you end up on this road?
To *try* and find non-virtual evidence of CC creep, or not.
If I do find progressive tilt, the case for creep resulting in global failure is strengthened considerably.
If I can find it increasing from zero to a significant amount pre-initiation, even more so.
guys - does this make sense?
Thank you for stating it explicitly; allow me to paraphrase into a sentence:
If you find progressive tilt pre-initiation in a still photograph, "the case for creep resulting in global failure is strengthened considerably."
I will defer to the engineers here as to whether your hypothesis is correct. I had thought that this was a settled issue.
Thank you for stating it explicitly; allow me to paraphrase into a sentence:
If you find progressive tilt pre-initiation in a still photograph, "the case for creep resulting in global failure is strengthened considerably."
Am not going to find progressive anything in a single image, now, am I ?
Photographic evidence of this creep would strengthen the current hypothesis. However, there is really no alternative on the table, so I would consider the amount of strengthening to be minimal -- "gold plating" so to speak.
It's also fair to assume that sufficiently high resolution data does not exist to dispute the structural creep. Thus, doing this test cannot give us a negative result -- either it supports what we know, or it provides no new information. It's not a very productive test to perform.
Mangoose
Muse
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I have a huge archive so I am going through them trying to find relevant images. Here is one pair; it is less than ideal because in one image the camera is zoomed much more than the other, so the resolution is quite different.
The first one here was taken at 9:04 AM (according to the EXIF, calibrated thanks to the shots later of the WTC2 collapse, which fix the time):
The second was taken at 9:30 AM:
They were both taken from the same location with the same camera.
I'll look to see if I have other or better examples.
The first one here was taken at 9:04 AM (according to the EXIF, calibrated thanks to the shots later of the WTC2 collapse, which fix the time):
The second was taken at 9:30 AM:
They were both taken from the same location with the same camera.
I'll look to see if I have other or better examples.
femr,
I thought the above were completely reasonable suggestions and requests.
For the 10th time, this is your project, not mine.
Your imagination.
who would this be? You?
The value in any work is in the work itself.
I don't deride poor work because if its author. I deride poor work because of its lack of rigor.
You claim to have been working on this project for some time. And found "negative results".
You claim to be able to perform sub-pixel resolution.
I asked you to describe the technique that you claim to have ALREADY employed (by name or verbal description), and you pitch a hissy fit.
I asked you to post some extreme blow ups of the images that you say you've already examined, so that we can see what the individual pixels look like at the building's edge, and you refuse & pitch a fit.
Color me unimpressed.
Care to show your math?
Tom
I thought the above were completely reasonable suggestions and requests.
For the 10th time, this is your project, not mine.
Your imagination.
who would this be? You?
The value in any work is in the work itself.
I don't deride poor work because if its author. I deride poor work because of its lack of rigor.
You claim to have been working on this project for some time. And found "negative results".
You claim to be able to perform sub-pixel resolution.
I asked you to describe the technique that you claim to have ALREADY employed (by name or verbal description), and you pitch a hissy fit.
I asked you to post some extreme blow ups of the images that you say you've already examined, so that we can see what the individual pixels look like at the building's edge, and you refuse & pitch a fit.
Color me unimpressed.
Care to show your math?
Tom
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If I find some tilt, I'll present it in detail. (And would probably have to shift my perspective somewhat in the process. Shock. Horror.)
Until then, nope. Not getting into a never-ending ridiculous discussion with you again Tom.
Thanks for explaining your misunderstadings earlier in this thread though.
As I've said from day one, I haven't found any progressive tilt in the available imagery.
Pretty much every post on this thread also concludes that it's very unlikely that any of the imagery will show progressive tilt at all.
Part of your initial assertion was that a) progressive tilt (visible for WTC 2), b) IB (both WTC 1 & 2) and c) engineering simulations was proof of CC creep.
I'm not saying there was no CC creep, but can't find progressive tilt and can't directly link IB to CC creep.
I'm grateful for any images that turn up, and will attempt to find said tilt, if only to prove to myself if the assertion of CC creep is correct.
If you object, that's fine.
Until then, nope. Not getting into a never-ending ridiculous discussion with you again Tom.
Thanks for explaining your misunderstadings earlier in this thread though.
As I've said from day one, I haven't found any progressive tilt in the available imagery.
Pretty much every post on this thread also concludes that it's very unlikely that any of the imagery will show progressive tilt at all.
Part of your initial assertion was that a) progressive tilt (visible for WTC 2), b) IB (both WTC 1 & 2) and c) engineering simulations was proof of CC creep.
I'm not saying there was no CC creep, but can't find progressive tilt and can't directly link IB to CC creep.
I'm grateful for any images that turn up, and will attempt to find said tilt, if only to prove to myself if the assertion of CC creep is correct.
If you object, that's fine.