Strange streak discussion: 2004 Dec 7 APOD

[Luis]

Victor [\b]

I ran the same simulation with some of the motion blurred insects from the "rods" websites. Even in the worst cases there is still colour information. The orignal image was smaller than 72 pixels

so the simulation is not as nice as the others.


I add the other two I made below

[Guest]

Meaning of AMATEUR

4. [adj] lacking professional skill or expertise; "a very amateurish job";
"inexpert but conscientious efforts"; "an unskilled painting"

Synonyms: amateurish, inexpert, nonprofessional, recreational, unpaid,
unprofessional, unskilled

Actually we are professionals (but we're goofing off).

[Guest]

As has been said before, the trail does appear to be straight but I think we're in agreement it's not really; rotating it to horizontal and squeezing left-to-right shows this fairly clearly.

Unless the camera optics is just a needle stick, any perfectly straight line would bend at the CCD "film". I believe. Have no figures though.

[Guest]

Meaning of AMATEUR

4. [adj] lacking professional skill or expertise; "a very amateurish job";
"inexpert but conscientious efforts"; "an unskilled painting"

Synonyms: amateurish, inexpert, nonprofessional, recreational, unpaid,
unprofessional, unskilled

And what do you think a board like this is? A scientific meeting?

Now that you are so intersted in the meaning of words, what about this one moron, I mean its meaning, according to the Oxford dictionary.

  • noun informal a stupid person.

  — DERIVATIVES moronic adjective.

  — ORIGIN from Greek moros ‘foolish’.

[Monkey]

Okay, you understand cryptic
I want before and after
Is there a connection?

[WEASEL BREATH]

Holy Mackeral...
If you folks spent half as much time in pursuit of something meaningful as you have done here, I'd be impressed.

No really...

But we all know what this image really is... so folks, go on, go home. Move along, nothing more to see here... break it up. Come on... go home. Show's over... move along now...

Oh? What is it?

Moe and Joe were in a plane accident. Their plane crashed into the sea and Moe and Joe swam to a small deserted island. After years had gone by, a pop bottle washes ashore. Moe picks it up and looks at it, holsing it so that Joe could see it. Clearly, it was half the length of Moe's body. Moe yelled: "Hey Joe, we've shrunk".

Or did they? ould the bottle really have been a new style, new fad, three foot bottle, or has Moe and Joe shrunk in size.?? Well, you just can't tell. You have no viable frame of reference.

Like this image. Speculate all day, you just need more information! Someone suggested: Go there! Hey, good idea. The rest is all just 'noise'.

[victorengel]

Victor,

if you see the images I posted above, they show that colour would be expected to be seen and structures would be visible in the static image of the "bug", when the flash went of. (Previous to image processing) Because the flash is very well defined, then you would expect to see other features in the image equally well defined, not only the silhouette of the bug. The bug blur is not consistent with what an optical instrument would produce. When an image is blurred, all of it is blurred, including bright reflections. Laws of physics apply to all waves, not only to the dim ones. Bright light is also blurred...

You would expect to see only the bug's shape if all of it was saturated, but this is not the case. The flash is clearly brighter. Note also that the foggy part of the bug is void of colour information and of any shades or structures, contrary to what a the image formation process predicts (A convolution of the object with the system PSF) and illustrated in the images I posted above.

I'm having trouble following you here. You say structure would be expected to be seen. However, you're making that conclusion based upon manipulation of an image that is not appropriate. That is my point. Your image shows a picture that has very little motion blur. Suppose in the image we're studying, that the camera happened to be focused on the bug (assuming it's a bug) and that there is no distracting ambient light. What I'm saying is that even before you start blurring the lens, you will have MOTION blur because, although the flash is brief, it is nevertheless not zero. An upper bound has been proferred at 1/1000 second, which, as someone pointed out, would cause a translation of the whole insect of several pixels. Also, assuming a wingbeat of 160 Hz, the wings would be very blurry. This is MOTION blur, not lens blur from being out of focus. You need to start with such an appropriately motion blurred subject for your analysis. Will the details you point out still be visible? Maybe not.

[Monkey]

Jesus, this is getting really strange. Could some kind soul (I mean kind and pleasant to dumb creatures) explain what is going on to us fruit eating acrobats who hang about in the forest.?

[victorengel]

I ran the same simulation with some of the motion blurred insects

OK. I spent a long time looking for a suitable image for a starting point. The original image is located here.
http://www.biozentrum.uni-wuerzburg.de/ ... /abb30.jpg
I took this image, filled in the distracting background, and then applied a motion blur roughly equivalent to what somebody calculated for 1/1000 second flash exposure (I used 1/3 of the insects body length). That resulted in this image.



This, in my opinion, is the kind of picture you should be using for your starting image. It's still not ideal, but it's about the best I could do picking an image off the web. Run this one through your program and see what you come up with. Note that this picture is clearly focused. It just has motion blur applied to match the duration of the flash. I have NOT done a color adjustment to match flash illumination. That would make the wings (upper portion of image appear bluer).

[victorengel]

This, in my opinion, is the kind of picture you should be using for your starting image. It's still not ideal, but it's about the best I could do picking an image off the web. Run this one through your program and see what you come up with. Note that this picture is clearly focused. It just has motion blur applied to match the duration of the flash. I have NOT done a color adjustment to match flash illumination. That would make the wings (upper portion of image appear bluer).

Whoops! I didn't mean to make it so small. Here's a larger version. This time I adjusted the color balance to be closer to what it would look like illuminated by flash.

[Guest]

Meaning of AMATEUR

4. [adj] lacking professional skill or expertise; "a very amateurish job";
"inexpert but conscientious efforts"; "an unskilled painting"

Synonyms: amateurish, inexpert, nonprofessional, recreational, unpaid,
unprofessional, unskilled

You need to find the right word for professionals exercising their expertise on this bulletin board. None are paid for posting here any more than any of the amateurs. Not professionals by any definition, if you keep things within their context.

[H0meAl0ne]

OK, I think I have it figured out now.

It's not a bug, it's a reindeer!

It stands to reason that this time of year Santa would be out doing dry runs in preparation for Christmas Eve. The photographer just happened to catch Santa and his sleigh on approach to Darwin.

The bright blob is Rudolf's nose. It looks yellowish because the light emitted by his nose is blue shifted due to Rudolph's velocity relative to the camera. (When you calaculate how many kilometers Santa has to travel in the one night you can see his sleigh has to approach an appreciable fraction of the speed of light).

The bluish 'wings' on either side of Rudolph's nose are actually his antlers. Give his hypersonic velocity at this point in his flight (minimum 1,000 kps, for details of this and all other calculations please see http://www.stwing.upenn.edu/~ruskine/hu ... claus.html ), we can conservatively predict the temperature of the leading edge of his antlers will reach several thousands degrees Centigrade, and will hence glow blue when seen edge on.

The 'streak' may be the ash of incandescent Christmas wrappings caused by frictional heating, but given the start of the streak well inside the edge of the picture and the lack of any dissipating smoke trail in the next pic, I would hazard a guess that what we are actually seeing is a motion blurred image of Santa and his sleigh!

"Ahah!" you cry. "But then why isn't there an appreciable bias in the red channel?" you ask.

My hypothesis is that Santa has 'stealthed' his sleigh in an aerodynamic fairing comprised of radar absorbant black material like the B2 Stealth bomber. As well as making Santa invisible to Darwin airport radar (I checked, there were no anomolous radar returns reported that afternoon) it also has the nice feature of absorbing a fair proportion of incident light.

I thought about taking a picture of the Stealth bomber in flight to compare to this image, but they are so hard to see I didn't know where one was. So instead I took a photo of a photo of the bomber, and just moved my camera a bit when I clicked the button. This gave me the motion blur I needed. Then I applied a Gaussian blur, anti-unsharp masking, added some noise and pinch of salt. The resultant image of the 'sleigh' is so hard to see I've actually lost it, so you'll just have to take my word that it looked like a darkish streak.

Hypotheses are no use unless they yield testable predictions, right? So here are mine...

1. Rudolf will have blackened leading edges to his antlers. I don't care how good any ablative surface is, it will show the effects of such heating. Unfortunately we can discard this test, as all it will show is that Rudolf travels at hypersonic speeds (or sticks his head in open fires), not that he was actually present in Darwin at that time.

2. The bluish 'antlers' are at an angle to the horizion and roughly perpendicular to the 'streak'. We should test to see if Rudolph banks his head and body appreciably when turning the sleigh. If he consistently maintains an upright posture with respect to Earth's gravity we can discard the Santa hypothesis.

3. If the security videos from the wharf have sound, they may have recorded a faint "Ho!, ho!, ho!" at the same time as the picture was taken. It may however take several months of sophisticated analysis to distinguish it from the normal ambient sounds of light bulbs blowing, meteroite impacts, people getting in and out of cars, lightning strikes, camera shutters, jet planes depositing chemtrails overhead and all those DAMN ANNOYING BUGS!!!

Where was I...oh yeah.

4. If this is indeed a trial run, given Santa's arrival in Darwin well before sunset, we can predict that either a) Australian children will start to find presents under their gum trees before they go to bed, or b) there's likely to be a large pile of reindeer dung somewhere nearby where they sat and waited till it got dark before proceeding with their deliveries. Can somebody ask the photographer to check the soles of his shoes?

[Dr Hans Blix]

OK, I've looked and looked and I can't see anything like what you're all talking about.

Oh, wait, this is the wrong thread....

[Forrest]

Close examination of picture with highest resolution possible appears to have streak originating from a cloud formation. Agree that light at the end of the streak is ball lightning, and it materialized closely enough to the light post to burn out the bulb's filament.[/list]

[walter(at)driedger(dot)ca]

It seems to me the shadow line is not straight; rather it looks ballistic. So much for shaddows of parts of the lamp. Furthermore, they would not be constant width.

Does the line actually intersect the end of a lampost? To me it looks like it strikes in the distant water. Has any tried asking the boat people if they heard anything?

A suggestion: Is it a piece of satellite debris?

I have 17 questions left.

[Guest]

A suggestion: Is it a piece of satellite debris?

If it were satellite debris striking the water, wouldn't there have been some surface disturbance in the picture taken 15 seconds later?

[J Joy]

I've scanned much of this discussion, but haven't seen whether or not there has been a follow up on the condition of the lamp. Is it known what the status is of the lamp? Was the bulb and or lens shattered? Or was it just inoperatable? Was there any damage to the lamp housing?

Also, I haven't seen anyone make note that it appears that the lower half of the "smoke, debris, vapor, or what ever" clearly seems to be in front of, or enveloping, the lamp post near the base. Note the pole is lighter in that area. I would say it rules out the possibility that the object was hitting the water beyond the lamp.

[victorengel]

I decided to try out a simulation. I started out with this picture of an insect (actually it's 2 insects, one carrying the other, but that doesn't matter at this point).


I took this image, rotated is slightly, filled in the distracting background, and then applied a motion blur roughly equivalent to what somebody calculated for 1/1000 second flash exposure (I used 1/3 of the insects body length). I also tweaked the colors slightly to be more like flash than afternoon sun. That resulted in this image.



One thing I notice immediately is that it looks like there are two wings rendered. Actually, one of them is really the blurred reflection from the body.

I resized it, applied a little Gaussian blur to simulate being out of focus, and pasted it as a new layer on the before image. I changed the blend mode to screen, since the effect of the flash is to add more light.

Then, on a new picture, I started with a black blob about the size of the insect's body and used Photoshop's motion blur to stretch it as far as it would stretch (to 999 pixels). I really wanted to stretch it a bit more, but I bumped into the Photoshop limit.

I then rotated by 33.6 degrees and pasted as a new layer. This layer I set to multiply, since the body was blocking the background light.

I then used the move tool to align the various components. I adjusted the lightness down a bit on the bug layer to more closely match what I'm trying to simulate (I figure this is reasonable since the brightness will be determined by distance and flash intensity, neither of which were used in computations thus far). Also, I noticed that I erred in doing the color adjustment from afternoon sun to flash. I adjusted the shadows as much as the highlights. This was an error that resulted in the supposedly black background to appear blue. This was easily fixed by setting a new blackpoint for the bug layer. Here is the result.

http://the-light.com/Photography/bugsimulation.jpg

I think it is important to point out that other than painting the detail out of the background in the original bug picture, I did no painting at all. Everything was manipulations to the entire layer.

Also, please note that the results are dependent on my source picture for the bug. It's likely a better source picture would give better results. But this was the best picture I could find.

[Guest]

Victor, I've seen how many posts you've put in - you have wayyy too much time on your hands!

[DC]

Maybe I did my math wrong on my grey diffs. I'll have to think it through again. What I eventually want, though I can't do it in my image processing program, is ((before + after)/2 - event) + 128

OK. Paintshop Pro works because it has diff AND subtract. But I had to modify your formula a bit to avoid clipping:

1. Average Before and After (call it mean)
2. Mean -50% contrast
3. Event -50% contrast
4. Mean +64 (128 results in clipping)
5. Mean minus Event
6. Negative image (because I think you got the sign backwards if you want the bright spot to look like a bright spot)
7. Adjust histogram

(image deleted, see page 87)

Again, I see a bright spot, but as before, it's clearly bounded by dark spots that offset it.

But wait! Is that another insect trail? Look about midway between our event flash and the top of the picture. There's a dark spot there. That dark spot seems to be a change in direction of a trajectory going up and to the left and down and to the right. Do you see it?

What happened to the color in your image?

I looked at my enhanced (orange colored) image, and I don't see another trail there. that was (before diff event), not double diff.

yeah, I got the sign backwards.

what I want is to try to arrange to do (event - (before + after)/2) +128, using real numbers rather than an image processing program. Hopefully I can do that before then end of the week. If I do I'll post some images, with the formula for the image, with no contrast tweaking. If I can get that far, there are at least two things I want to try.

[victorengel]

What happened to the color in your image?

Maybe the radio button that said luminosity?

[DC]

I think it is good someone is trying to reproduce this effect with bugs, which I don't think will work. The image below is an invert of my previous double diff. I have labeled the image components the way I understand the bug theory. My concerns are:

The wing/thorax refections are very narrow, which cannot be reproduced with a blur effect. The wing reflections attach too neatly, with almost geometrical precision, to the thorax reflections. There is no room for the required connectional anatomy here. Also, the thoraxic reflection should be a complete circle, which should not intersect the abdominal oval.

(As an aside, notice the pink and yellow JPG artifacts around my drawn images, which illustrates the kind of distortion we are dealing with)

[DC]

The lightness I think I am seeing in this picture goes the other way, which I've circled in purple

I think I see what you are talking about. In fact, looking at the original diff image by Douglass on Page 10, there are several of these vertically oriented light streaks. They appear to be associated with gaps in the trees.

I am looking for an way to enhance the vertical streaks so they appear more obvious. I know what I want to try, but I don't know if I can implement it right away. That should tell me if the streaks are associated with the gaps in the trees.

(Still working my way forward from about page 86, with complications from a partly broken ethernet connector)

[Guest]

1. I see something differently in your image, not apparent in other images posted. See two wider trails on each side of the "body" trail, which have the width of, and which I beleive are, the bug's wings.

I noticed that too, but I was not confident enough in what I was seeing to make a comment before. I took a look at the whole image, and it did not seem to be present except for in the crop shown here.

I see that too. I'm beginning to think the wing beats are not resolved at all, so that no amount of FFT processing will bring them out. They don't appear to be resolved in that faint shadow. I think the problem is that the bee is heading at an angle away from the camera, and that we are seeing it mostly from behind. Note the foreshortened appearance of the bugs body, and the slight tapering down of the shadow. There is enough of an angle that the wings "flaps" are overlapping in the image. I think the peaks in the summed FFT are all we're going to get.

I think the explanation of the "flash" is that the insect is a rather dark bee with a yellow pollen load or a highly reflective yellow patch on it's abdomen. The wings are moving enough during the camera flash to provide additional "blur" over and above that from out-of-focus distance, and are transparent enough, that they match the dark body in reflectance, but the yellow pollen or patch is reflecting much more light back to the camera. There was a picture of such an Australian bee back about page 60 in this thread that had a very bright yellow ventral side on its abdomen.

I didn't come up with wider trails on either side of the body. I am going to try to make a better version of this image later.

[DC]

This is a sample of what the previous image looked like before I enhanced the contrast, etc.