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Digital Video Capture and High Frame Rates?
Jeff asks: "So the folks at a place called Conniption Films (great name) developed a camera called the Millisecond Camera which can shoot 12,000 frames of film a second. I read the article and thought 'Hmm that's neat' but then realized they were still using an analog process for shooting this highspeed film. Being a geek, not necessarily into the film side of things but curious nonetheless, I wonder, shouldn't a computer be able to do a better job of such a thing? They say the film runs around a spindle going 500 mph (!). Wouldn't that be prone to failure and use alot of energy? Wouldn't it be more appropriate, easier, and overall cheaper to just hook up a high res CCD to a beowulf </duck> cluster of 2 ghz+ machines and capture high speed images that way? Why hasn't it been done yet? Or has it and I haven't seen it yet?" I did a double-take, when I first read this question, and then got curious and did a little digging. Turns out, high frame rates are not exclusive to the analog photography world, and to illustrate my point, I provide this link. It's woefully short on details, and the explanations as to why a camera that can record 1M frames per second is limited to a playback of only 103 frames, but the technology is out there. Has anyone seen any other digital cameras out there with high frame-rates? What visual mischief could you aspiring photographers get into with such a camera?
are often a bit delayed. they're slow. that's it.
Film is much faster than CCDs, still. If there's enough light, film is much faster and better quality.
The problem is the bandwidth.
Small, 8bit color uncompressed movie at 300x300 pixels would require something like 8 billion bits per second. (300 * 300 * 12000 * 8)
Now we probably want more resolution & a higher bit depth, so multiply apporpriatly.
What are we going to use to transfer that much data around a cluster? Or even just from the camera to the cluster?
With a frame rate that high, you could mount the camera on some sort of circular rail system and move it around a relatively still object, to get matrix-like effects.
It's woefully short on details, and the explanations as to why a camera that can record 1M frames per second is limited to a playback of only 103 frames [...]
Memory problems, I suppose. They say each pixel is its own memory. I guess that getting 1 million frames per second through any kind of bus to any kind of memory is going to be tough. AGP isn't going to cut it. ;)
You bet. A FOAF(friend of a friend) is working with some folks developing some very cool high speed cams for all kinds of research. They're using CMOS sensors instead of CCD's. These allow you to capture images as fast as you want (tens of thousands of fps) with a corresponding reduction in resolution.
If you could get a hold of a cmos image sensor you could probably rig up something similar but remember those data rates are INCREDIBLY high. Also, that means the length of the shot tends to be fairly short.
The explanation as to why it can only play back 103 frames is QUITE clear... the chip has 103 "on-chip" memory buffers per sensor, and they get cyclicly overwritten with the last 103 frames.
This overcomes the bottleneck of trying to transfer data off the CCD at such high frame rates in real time, but limits you to "downloading" the last 103 frames after-the fact from the chip.
MadCow.
I used to have a sig, but I set it free and it never came back.
A quick calculation on the bandwidth of capturing 12000 SVGA-resolution full color frames per second:
1024 (width) * 768 (height) * 4 (32-bit color) * 12000 (fps) = 377,487,360,00 bytes/second (35 Gbytes/s)
So no wonder they use film...
CCD simply needs a few milliseconds to regain their 0-volt signal level again before they can emit a new pulse. This recoverytime makes it unsuitable for high speed filming. Helas.
What visual mischief could you aspiring photographers get into with such a camera?
I have to say the obligatory ultra slo mo pron!
Actually fact is, the adult industry often drives the need for newer technologies I've read.
'nuff said
also consider that most of the time, people that are interested in such frame rates, are also *very* interested in having detailed high-resolution frames of the event at 'interesting' times.
This probably means having to shoot images of around 4-6 megapixels, and I really don't see any way of doing that at the speed needed for this kind of application.
The only way might be exactly what the poster of the topic didn't grasp: have a camera that can take 100-1000 pictures at a 1Mpics/sec frame rate and store them in ultra-fast local memory, and transfer them out at leisure, with a good triggering setup, 100-1000 microseconds worth of data might just be enough for certain applications.
-- the cake is a lie
It may shoot at a rate of 12,000 frames per second, but the film is only 120 frames long.
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To achieve this sort of bandwidth, memory and ccd would have to be on the same die ! We would have similar architectures as for cpu's with the ccd as the core, the 1st and 2nd level cache to store 1 or 2 seconds of film, that would be transferred after recording to the outside world - ie the main cpu of the computer that would transfer the data to disc. evolving design would allow to stretch the capacity of this architecture - higher resolution or longer recordings. But be sure of one thing - it will take several years to achieve the same quality you get today for analog devices.
I have a Sony DSC-F707. It takes beautiful pictures but only has enough buffer memory for 3 burst pictures. With higher resolution images (akin to film level quality) you'd need way more memory and throughput than can be supported with traditional flash memory. A external drive mechanism won't work either (i.e. bluetooth) because of the throughput necessary to sustain something at the rate discussed. I mean camera's today can't even do mpeg compression decently.
As any /. reader knows however, it's only a matter of time before silicon catches up with whatever it's chasing.
At 640x240x24, you're talking 7372800 bits per frame. At 1000 frames/second, we'd need to be transferring 7Gbps. That would be a bit hard to handle. You could cut the rate by dropping colors. At B/W, it'd be pretty manageable, but that's probably not what you want. You probably also want higher resolution. No matter what, you wouldn't be able to swallow the stream for long.
Oh, and by the way. The confusion about a million frames/second versus 103 was just poor word choice in the article. What they mean is a 1 microsecond shutter speed - 1 microsecond frames with 9707 microsecond gaps. Great stop-action to cut blurring, but manageable transfer rates.
A. El Gammal, et al. published a 10,000fps imager with a 352x288 pixel resolution. This guy can maintain the full speed indefinately. Unfortunately is it not a commercial device, but something similar will probably be available within a few years.
Kleinfelder, S. SukHwan Lim Xinqiao Liu El Gamal, A. "A 10000 frames/s CMOS digital pixel sensor", Solid-State Circuits, IEEE Journal of. v38 n12, pp. 2049-2059. Feb. 2001.
The abstact is as follows:
A 352 x 288 pixel CMOS image sensor chip with per-pixel single-slope ADC and dynamic memory in a standard digital 0.18um CMOS process is described. The chip performs "snapshot" image acquisition, parallel 8-bit A/D conversion, and digital readout at continuous rate of 10000 frames/s or 1 Gpixels/s with power consumption of 50 mW. Each pixel consists of a photogate circuit, a three-stage comparator, and an 8-bit 3T dynamic memory comprising a total of 37 transistors in 9.4x9.4 um with a fill factor of 15%. The photogate quantum efficiency is 13.6%, and the sensor conversion gain is 13.1uV/e. At 1000 frames/s, measured integral nonlinearity is 0.22% over a 1-V range, rms temporal noise with digital CDS is 0.15%, and rms FPN with digital CDS is 0.027%. When operated at low frame rates, on-chip power management circuits permit complete powerdown between each frame conversion and readout. The digitized pixel data is read out over a 64-bit (8-pixel) wide bus operating at 167 MHz, i.e., over 1.33 GB/s. The chip is suitable for general high-speed imaging applications as well as for the implementation of several still and standard video rate applications that benefit from high-speed capture, such as dynamic range enhancement, motion estimation and compensation, and image stabilization.
it would suck to take a beowulf cluster to outdoor locations.
You normaly use this kind of speed if you want to do motion analysis.
Say your company does crash tests or you want to find out what happens when something explodes.
if you frame size was 30cm squared (about a foot) then 12000 frames per second would allow you to capture 10 frames of somthing travelling at about the speed of sound(i think my math is correct!)
or a few frames of a bullet.
thank God the internet isn't a human right.
From reading the article, the bandwidth problem was solved by giving each pixel of the camera it's own memory. One problem that I can see is that: This is going to eat space on the chip that would normally be used for imaging. If you put too much memory around a pixel, you're going to start suffering in the quality of the image. (and they already had to increase the size of each pixel to be able to capture the light fast enough)
It would seem that they pegged the usable tradeoff at 103 samples per pixel, so that's how many images you can store.
Free Software: Like love, it grows best when given away.
Many people seem to think that digital image quality is superior to analog. This is untrue. So anything you want to analyze by looking at it, you want analog film. Digital advantages are: computer analysis, reproduceability.
Now to your question, the primary digital disadvantage is bandwidth.
Digital images have a very specific size: 1024x768x32 = 3 MegaBytes
Analog images have virtually unlimited sizes (infinite x infinite x infinite). Some people have tried to estimate the resolution of analog images, and they best they come up with is a vertical and horizontal resolution in the thousands, however this is unreasonable. Analog images are more detailed than that.
Now bandwidth calculation:
(size of single frame)(frame rate) = (bandwidth)
(3MB)(12000) = 36000 MBps
So, we are looking at processing and storing about 3.6 Gigabytes per second. I mean processing because we want to use lossless compression, and this would require some very specialized hardware to handle this framerate. This cannot be processed or stored in real time on any modern generalized computer. It should be possible to build a specialized machine to accomplish this.
I have discounted limitations in CCD speed, possibility of using mulitple cameras, high-end hardware I don't know about.
Conclusions: "Digital" is not the panacea. Visual image analysis should always be done with analog film. Digitization is good for reproducing images, and transporting them intact. A camera that does 12k fps is mostly for image analysis of high velocity and high acceleration objects, for analysis in a lab. There are applications of high speed digital imagery, but I don't know any offhand.
Finally, using a computer to process the resulting data takes a substantial amount processing time. So the answer to the question "why not use digital cameras" is "why would you need to?" If you can justify the need, do it. It will require, however, substantial resources which also need to be justified.
For amateur photography, don't worry about a 12k fps camera, stick with the 30fps DV handicams.
Torsten
There are a lot of limits when it comes to cameras connected to PC's. I've worked in a lab where we used cameras that generated 640x480x4 (32 bit color) frames at 60 Hz. Guess what. You can't even buy a HD that can sustain that kind of transfer rate for any period of time. Good thing those computers had about a gig of ram each ;-)
There is actually a few limitations. Bandwidth is the most important one. Here you're looking at the connection between camera and the computer. We used special frame grabber boards, fireware or USB - well... nothing that I know of can handle 12,000 Hz. Next, somewhat smaller limitation is the bandwidth to memory. When you're talking about 12,000 Hz - that will become a factor. And of course - unless you've got about 40 Gigs of Ram (at least) you would want to save the stream. There are Video Vaults which are basically raid arrays, but again - they can't handle this kind of data stream.
Technology is coming along though. The new CMOS based cameras can have fairly high frame rates. You can actually select between resolution and framerate. Last time I checked the fastest they could go was about 500fps (at low resolution), the limit being again the link between the camera and PC. I believe the theoretical limit of the CMOS type camera is at either 5000 or 8000 fps (I don't really remember which - sorry).
FreeBSD is for acne clueless snobs. Who cares about their little baby sandbox. FreeBSD is dead anyway. Send JKH some Clearasil. He needs it bad.
"why the hell would anybody need 12000 frames per second. The human eye cant process all that plus nothing happens so fast you need 12000 shots of it in a second. This is just plain stupid and its a waste of film."
Because certian events, despite what you might think, *do* occur within 1000ths of a second. (The fireball from a nucelar blast for instance.)
Good cammera's shutter speeds tend to go up to 1/1000th of a second, and can go up to 1/8000th.
As far as the humman eye comment, well, just because you record at 12000 fps, doesn't mean you play it back at 12000 fps...
As some have said already... the bandwidth is the problem, but even after that, you still have to write it pretty damn fast... so here is the obvious solution... a cluster... per pixel.
Rather than just have ram per pixel as the article says they did, for digital, have a single computer unit per pixel. So say you want a 4megapixel resolution full motion video. Then you get 4 million computers each processing a single pixel. That should be plenty fast enough to get some very high speeds (assuming the ccd can handle it).
Of course, the problem now is to tie all that data together into a single video... and even then to find a machine to play something like that, though i supposed you could take each 4 million machines and have them each play their data into a single pixel on an lcd.
But then, why not just use film?
On the pure digital front, there are units that can record 1000 FPS continuous at 512 x 512 pixels. The system is data-rate limited. The imager can go much faster; if you cut the image size down to 32x128 pixels, you can get 32K frames/sec. At 128 x 128, you can get 11.2K frames/sec. The data goes into a buffer in the control unit (1 GB, typically), and is read out via FireWire. So this system can take a lot more frames than the device described in the article, which stores the images in memory within the imager and can only store 100 images or so.
--Mike
"Not an actor, but he plays one on TV."
Answer to first question: Ever heard of Slow-Motion? Record at 12,000 fps, play back at 30 fps, and it basically slows down time so you can see really fast events moving slowly.
Answer to second question: No, you didn't
Carpe Cerevisi - Seize the Beer
Most beowulfs use a gigE interconnect... perhaps have two or three NICs per node, one for the system interconnect, and the other two for connection to the CCD. The CCD module could easily be broken down into a grid of virtual segments, each with its own cache and a gigE interconnect.
Another option is to wait for 10gigE (along with the rest of the supercomputing world) or go with Myrinet, which has recently broken the 1 gigabit barrier.
As I pointed out in another post, a good option would be to use several gigE interconnects to connect the CCD module to the many nodes of a beowulf cluster. Besides, you're going to need a cluster to manage that much data anyway.
377,487,360,00
You may have never realized, but you're supposed to combine digits by groups of 3 starting from the *right*. Like this: 37,748,736,000
Picture an image sensor as a one-inch-square array of pixels. If the frame rate is 30 per second, then 1/30 (3.3%) of the light that falls on the array makes up each frame.
If the frame rate is 12k/second then only 1/12000 (0.0083%) of the light can be used to make each frame. That means that the CCD must be 4000 times more sensitive to light, or you must use a light source that is 4000 times brighter, to get the same results.
And that ignores the fact that solid state light-to-electricity convertors like CCDs have a certain "latency" or "stickiness". Like the effect that the eye sees after a watching a flashbulb, CCDs suffer from after-images, and the brighter the light the worse the problem. Film doesn't have that problem because each frame is exposed on a new "receptor", i.e. a new piece of film.
A high-res CCD could be viewed as a collection of low-res CCDs. So, design a high-res CCD that has multiple output paths. Each output path would go to a seperate computer and the data could then be recombined to construct the original frames.
The data from a 1280x1024 CCD could be split into 16 320x256 segments.
Of course someone's got to make the CCD, and I imagine having 16 computers connected to the same CCD probably poses some interesting problems. But, I'm sure that it is solvable.
Shouldn't it be ?
You can get around any bandwidth issues with a sufficiently large amount of cabling. The whole idea of doing this in parellel implies that. Anyway, compare the bandwidth of digital photography with the physical bandwidth of looping film through an eyepiece at 12,000 frames per second and you come up with a very different problem -- you've got to use TINY film, with an effective resolution much lower than what some of you linux numbercrunchers are assuming. "SVGA resolutions?" Think more like 320x240 -- and don't expect more than a few seconds per cannister, high costs, etc.
.000083 s. With low light, you need extremely sensitive equipment to even detect it and even more sensitive equipment to detect the subtle variations in wavelength that make up colors. Today's CCD cameras are very slow to register intensity light -- much slower than film. The chemical reaction in film triggered by exposure can be controlled much better, simply by changing the tolerance of the film -- which is why your high end, high speed shutter digital cameras are so godawful expensive. The $2500 Canon I've been looking at has roughly the same shutter speed as an equivalent $300 film camera. The extra price is NOT a "coolness" tax...it's for the set of three extremely high res CCD sensors and the chips capable of processing their information at that speed. My film prof used to say "digital ain't digital"...there's a quality factor of all digital electronics that can be poiled down to the quality of interpolation, quality of the ADC and of transistors leading up to it.
No, the problem is light itself. You don't get much of it captured with a shutter speed of
CCD kind of sucks, man. For all its glorious promise, the best CCD chipsets aren't all that much better than the wonderful X-10 spycam.
Hey freaks: now you're ju
Because certian events, despite what you might
think, *do* occur within 1000ths of a second
Yes, like when I get fragged playing quake.
Michael
There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
Appending my own post... Obviously that should be 400 not 4000. But in an industry that makes a big deal about a 10% sensitivity improvement, it might as well be 4,000,000.
There's also a different sort of CCD highspeed camera that's used in various types of racing.
That system uses a single row of pixels which can be scanned at extremely high rates - the picture is built from objects moving in front of the pickup row, rather than the camera actually taking a full-resolution image.
Sort of a high-tech slit-camera.
Perhaps not 100% on-topic, but still interesting.
The other factor when talking about extreme high-speed photography (when people are calculating bandwidth):
Most really high-speed cameras shoot in black and white afaik.
If you drop the calculations from 32bpp down to 8bpp for a nic greyscale image, you're starting to get to manageable numbers... Also, adding cheap hardware based compression (RLE or the like), would be able to reduce the data stream to even more manageable levels.
You're not going to be able to shoot 6 megapixel pictures that fast, but 320x240 or 640x480 images should be possible at high framerates. I doubt it would replace film, but it might be handy for quick playback without having to get negs developed.
If you watch the "Bad Boys" DVD (the Will/Martin ver of Bad Boys), they have some very cool high-speed photography of different guns being fired into different objects. They used some sort of kodak high speed imager afaik - around 2000fps.
"Nothing strengthens authority so much as silence." - Charles de Gaulle
IN fysics class i picked up the trick to compute the speed of light. the full method is a bit lenghty to explain, but the whole trick was the use of a rotating mirror....
One creates a semi circular mirror by glueing eg 40 small mirrors on a circular object. rotating this object (really fast, original example was driven by steam!) will project the image slightly displaced. put a shutter in front (also really fast, no problem) and the image will appear on a new location each time, till it reaches the end and will start at the beginning again.
(this can be done in horizontal and vertical direction, like a CRT monitor)
wether to project on unique CMOS chips or on one very large CMOS is up to the tech guys.
But i think this kinda trick could make it possible to parralize the process needed for the data to get processed.
Why are other peoples sig's always more witty ???
There have been many good replies to this thread, though most are talking theory, some experimental at best. A camera module with the ability to capture 12,000 high resolution frames per second is bound to cost a fortune, and I really doubt there will be much competition for a long time. Perhaps a cheaper alternative would be to purchase several currently-available high speed CCD/CMOS camera modules and use a series of mirrors and lenses to allow the cameras to work together in a round-robin fashion to achieve the a much higher framerate. This would certainly keep the project from being locked into proprietary hardware -- be it a single interface type, manufacturer, or other monopolistic attribute.
The idea of "parallel" items is nothing new, we've already seen success with drives, clusters, and even an array of projectors to create a high resolution projected wall.
Just a thought...
As far as the humman eye comment, well, just because you record at 12000 fps, doesn't mean you play it back at 12000 fps...
:-)
Well, don't tell that to the hard core gamers - I'm sure some of them would pay alot of money to get a video card that does even 1000 fps.
Actually, motion looks fairly fluid above 25 frames per second (although your monitor will need to refresh at least 3 times that speed to avoid flicker).
There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
C.E.M. Strauss, "Synthetic Array Heterodyne Detection: A single Element Detector Acts As An Array", Optics Letters, Vol 19, No. 20, 1609(1994)
and
B.J. Cooke, A.E. Galbraith, B.E. Laubscher, C.E.M. Strauss, N.L. Olivias, Grubler, A.W. laser field Imaging through fourier Transform Hetrodyne, proc of SPIE, 3707, 390-408, (1999)
the problem with pixelated detectors is reading out the darn pixels fast enough. Normally this is done by some sort of bucket brigade across the ccd or some sort of serial memory access across a cmos array. very slow.
In My approach I solved this problem by multiplexing all of the pixel signals onto the same single wire. Each pixel when activated creates an osciliory signal at a unique frequency. All of these are combined on a single wire out put (amplified by a single fast amplifier) and then the AC signal is digitized by a single fast digitizer and streamed to a hard disk. The frame rate is determined by the frequency separation between the pixels, so if the oscillation frequency is a megahertz then a frame can be resolved every microsecond. This process is continuos and can go on for as long as you have disk space.
the other cool feature is that the chip you do this on is a single pixel chip! not a pixelated array. the pixels come from painting the chip with a rainbow of light. for a 1-D example, imagine red light on the left edge and blue light on the right. when a reference signal comes in it beats with the light. the beat frequency that gets ouput is determined by where (left to right) the incoming beam hit.
of course the good news and the bad news is that this is intended for active remote sensing where one is illumunating a target with a single frequency laser. It does not work with ambient light (note the second articele referenced above will work with polychormatic light) . The good news is that the detection method is hetrodyne detection which has shot noise limited detection sensitivity even on a crappy photo detector. thus the system is capable of detecting a single photon of light.
anyone else remember eg&g's high speed nuke cameras?
Rapatronic Camera Shots
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One of the cool things about growing up on a military R&D base was the school science-class tours. I remember seeing one of the high-speed film cameras in the 70's. The cameras were used to study missile impacts, explosions and other things that happened too fast to see.
In a traditional film camera the film is moved into position by a sprocket and then the rotating shutter allows light to pass then occludes the light while the sprocket pulls the next frame into position. At an average film speed that is close to the speed of sound the normal techniques are useless.
In order to keep the film moving and to maximize the amount of light available for exposure the film moves at a constant speed while a prism is spun at high speed to keep each frame following the moving film. The 16mm film was made of mylar (strong enough that you could hoist yourself up with it) due to the stresses involved and still they had to vacuum out the disentigrated bits of the last 10 feet or so that whipped through the camera at the end of each run.
I suspect some of the same techniques could be used for digital - ie many sensors being used sequentially to deal with CCD response and bandwidth constraints. For some uses I imagine multiple cameras timed to shoot in close succession (like they did for some of the special effects in The Matrix) could be used.
High-speed photography is quite cool and opens up a view to the world of the instantaneous like the series of shots of a nuclear explosion that were done at such high speed that even many frames into the film the fireball hasn't even made its way out of the shack that the bomb was in.
Immediately following the signal was a huge EMP burst. Immediately following that was the fireball, reducing the wire to plasma....
Needless to say, the engineering required to capture the data without blowing the hell out of the equipment was non-trivial. It also points out that there are many places where extremely high capture rates are required.
Some very interesting things happen very quickly....
Let's do some arithmetic:
The wavelength of visible light (in a vacuum) is between 4x10^(-7) and 7x10^(-7) m.
The speed of light is 3x10^8 m/s (in a vacuum). Planck's constant is 6.6x10^(-34) J s.
Put these together, and a single photon of visible light has an energy of between 2.8x10^(-19) and 5x10^(-19) J.
Suppose you want to get 24-bit colour. As an absolute minimum, you'll want to be able to detect 4096 photons per colour per pixel per frame. CCDs are typically 50% efficient, which means you need 256*3*2 incoming photons per pixel. At, say, 1024x1024 pixels and a million frames per second, that means 3*4096*2*1024*1024*1000000 = 2.6x10^16 photons per second, at an average energy of 3.9x10^(-19) J each.
That's an absolute minimum of 1.0x10^(-2) W of incoming radiation.
How much light is available? Well, at "bright sunlight" is approximately 30 W/m^2 of visible light.
That means that you'd need an aperture roughly 28mm across... which isn't impossible, but is certainly not going to be desireable.
So how does ultra-fast photography work? They use really bright flashes of light... which is why you don't want to be filmed for more than a fraction of a second at once.
Tarsnap: Online backups for the truly paranoid
The US Army is testing ultra-high speed CCDs for future use on armored transport vehicles and tanks. These cameras combined with some very nice CPUs will actually determine the exact location of an incoming projectile and its rate of speed in time to deploy a defensive mechanism such as a short-burst magnetic pulse -- this would cut energy needs down to realistic levels while still providing defensive capabilities. The big problem with high-energy defensive systems has always been that they suck up way too much juice to last long, but with this system, they can make the tanks and such nearly invulnerable (until they run over a landmine, anyway :) ).
No..... is html, is something else.
A description of how it works in stilted patent language can be read on line here
This way while one CCD sensor is in use, the other ones are discharging to 0.
The hurdle becomes finding a way to either block the CCDs that are discharging (if the pixels are grouped), or to mechanically re-direct the light to the CCDs if they're completely separate devices (perhaps a spinning prism?).
At my work we use the Phantom Cameras from visiblesolutions.com We can get up to 14000 fps (though not at a high res). 1000 fps is possible at 1024x1024. The cameras have 2 to 4 gig of ram on-board with a circular buffer. After the event, you can take your time offloading the data via 1394.
OOooh. Even better: Rotating 45 degree mirror redirecting the light to the individual CCDs. You could have a lot of them this way, and have only one lens. :)
The problems abound and are covered quite clearly in other posts.
How I would tackle the problem is to setup a series of CCD (Foveon's X3 would be my choice), with each pixel element feed directly into a huge RAM cache where the data could be loaded off into yet slower storage.
Since we had to deal with charge time (hence the first C in CCD) of 1ms, we'd need 1000 CCDs each with their own data cache and so on.
Then comes the problem of making an image - since we'd be dealing with 1000 CCDs, we're going to have to figure out how to place each pixel so than when that pixel's series fires, we can capture an image which would look like any other series' image. So this is what you'd be dealing with:
DATA RATE = 3 * (W*H) * 1000 * Time Duration
For giggles:
3*(1024*768) * 1000 * 1s = 2,414,592,000,000 (2,358,000,000 Bytes per second).[1]
Thank you, I'd like a stiff drink now, and film looks mighty good.
[1] If I didn't fuck up my math...
III.IIVIVIXIIVIVIIIVVIIIIXVIIIXIIIIIIIIVIIIIVVIII
We use 1 and 5 Mframe/sec cameras on the Pegasus project. They are useful in toriodal fusion experiments because the plasma bursts are so short (~a couple ms). Sean
The latest Cinefex has an article (dead tree only) on Episode 2, and it talks about the fact that Lucas shot the movie entirely with digital cameras. The SFX folks had some troubles because they're used to using high-speed cameras for explosions and model filming. The digital video camera that they used was fixed at 24fps. (I don't think they said what resolution it recorded at though.) My guess is that the SFX folks would love a variable speed, high-rez digital video camera.
Slow-mo capture of hot grits being poured down Natalie Portman's pants...?
Each frame taken has to be exposed long enough to pick up enough photons of light to get an image. If you want 8 bit resolution, you need to give it enough time to get up to 255 photons; 4095 for 12 bit, etc. Thus, in average room lighting, if you try to take more than a few hundred frames a second @ 8 bits you just get blackness on the output. For a million independent frames a second to show up, you'd probably have to be standing on the sun.
Redlake MASD has been advertising its handheld MotionMeter, a high speed digital imaging system, for under $5000. It claims frame rates up to 1000 fps and an image buffer up to 4K frames. I'm not sure how much of these maximum specs the $5K buys you, though.
The originator of the message thread seems to think digital is preferable and better than analog on every aspect, wich is false. I.E. Not true...
digital is more handy and portable, but analog is more in direct connection with the natural phenomenon you are trying to capture. therefore the analog nature af a 12,000 FPS camera...
Why? I remember when I first got a digital video camera, the first thing I went out and did was set it up on a tripod, pointing to a full pop bottle, and then shoot it. I ran back to my computer, put it into Premiere, slowed it down, and was vastly dissapointed that I couldn't see every instant of the process. Mostly the bottle's there, then in the next frame, the bottle has a hole in it, then it's up in the air, and it falls. How much fun would it be to see the bullet make its way towards the bottle, see every moment of the impact, and the exit of the bullet in a fine spray of mist? I'd love to shoot in 1000 fps instead of 29.whatever.
Mod my comments down. It'll be fun.
Kinki University in Japan led the research, sponsored by the Promotion and Mutual Aid Corporation for Private Schools of Japan...
That's a mistranslation. The correct English translation would be Corporation for Private Schoolgirls of Japan
God, I love Kinki University.
put the what in the where?
Ever seen the inside of a car impact test facility? You've seen this on some commercials, even if you didn't realize what you were looking at. There's a huge bank of lights on during a test. Literally hundreds of lights, each of them on par with the lights used to light stadiums.
They have to be turned on in sequence, because if you tried to turn them all on at once, the current draw would kill the power grid. This despite the extra-hyper-ultra-industrial strength wiring into the grid.
You also can't leave them on for more then a few seconds because the heat generated burns them out. (It is actually a challenge to balance these two conflicting priorities, to turn them on quickly, yet slowly.)
The power draw for a single test is enough that they actively try to minimize the amount of time these lights are on. This despite the fact that electicity is normally so cheap we really don't think about it much. (Think in business terms; this means it's worth someone who is being paid $50+/hour to actively spend time worrying about how to minimize the time these lights are drawing current.)
All of this for the ultra-high-speed photography that takes place. I don't recall exactly how bright they said it was in the facility I was in, but I think it blows sunlight away by several times.
I mention this as an example application where "bright flashes of light" (emphasis mine) aren't practical, so they have to go whole hog. Kinda cool.
When testing the railgun, just before it fires, you hear a very fast rev-up sound that turns into a whine then disappears, then you hear CLUNK!
I always thought this was some sort of capacitor charger at work, turns out it's the 1,000,000 frame per second camera revving up to speed to record the event of interest.
In the 80s.
So the obvious (well, to me) solution would be to make a rotating drum of CCDs. The timing would be tricky, you may have to reassemble you picture later, but it is technically doable.
An analog/digital convergance solution.
The neat thing about that, is when CCDs and transfer rates get faster, you can just up the speed of the drum, to get even faster picture rates.
No! It's a *SIG*. Keep the Special Interest Groups away! (Con joke!)
If you've watched the US Open Tennis in the past few years, you've seen the 'Mac-Cam" that shows super slow motion of the ball as it hits the line.
Also, if you watch Formula 1 auto racing (Speed channel in the US) then they usually pepper their broadcasts with super slow motion shots of the cars negotiating the chicanes.
You can cut a lot of the data rate, by sampling in grey scales, not full colour - most applications, such as ballistics, only require monochrome imaging.
Why the hell would anyone want more than 640K in their computers?
Capability drives application.
Incidently, I'd like to point out that high speed cameras do *not* use traditional shutters, (serious mechanics problem there!), as far as I know, the film moves *constantly* and images are reflected by a rotating prism or mirror, or similar arrangement.
Do you really think that sprocket holes would stand up to 12,000 frames per second? Errr, no.
My solution to this problem, (and this is very novel, and maybe I should patent it), would be to use a high-persistance CRT to store the image...
Basically, it would work like this:
A rotating prism/mirror reflects the images in sequence across the face of a monochrome CRT, exciting the phosphors behind it. Then an electron gun scans the screen, and reads the state of the phosphors, by trying to light them - high current flow, and they were previously dark, low current flow, and they were previously light.
High persistance CRTs were used to store data in 60s and 70s computers, but my idea of reflecting an image on to the CRT to be read off by the electron beam is, as far as I am aware, unique.
Nobody is permitted to nick this idea and patent it, alright? You saw it *here* on Slashdot first.
My friend thought of this 10 years ago. Problems include focussing, because even if you could find a flat screen mono CRT, you still need to focus through the thick glass, and inside it might still be curved.
It's also not sensitive enough. Please do a search on stuff like image orthicon and how they needed a small nova to light up people, etc...
Why not use 40 x 1000fps cameras setup in a round robin capture style? (or any other managable combination thereof). All the cameras are timed so that after the first camera snaps a shot, the others go off sequentially, and as the last takes its shot, the first is ready to go again.
This is the same approach as when comparing clusters to mainframes..
If a problem seems to large to tackle, why not break it down into smaller, more managable chunks?
E
[1] Image Quality [2] Bandwidth [3] Frames per Second (speed)
/. finially decided to run an article on this topic :) although it is plain to see that some of you are confused about what this technology is used for. Also I found it quite humorus that the one guy quoted image size of what he assumed the image sensor as 1024x768 which is the most commonly used screen resolution but probably has never been a image sensor size. Here is a good reminder from micron concerning the differences in resolutions. Most image sensors that are developed are of the same size in both dimensions. Not all but most.
The other posters are correct pointing out the limitations inherent in high speed digital photography because today there are certainly a few that need to be over come before the transition can be made. With the speed of memory technology we are able to store a limited amount of image data on camera and allow for this to be transfered after capture has taken place. Already we see the beginings of high speed digitals that can be run indefinately with a loss in image quality. When you take out color completely and drop frame resolution than there is alot you can make a digital camera do. The reason that you have a loss in image quality as the speed increases is because the CCD / CMOS / CIF [Common Interchange Format] can't read out the image data fast enough between frames. Current implementations make one chip act as two whereby only one half of the imager captures at a time while the other half is busy transferring its data.
Readers should keep in mind that CMOS is used primarly in video because you can change the analog image data over to a digital value much quicker since there are more A/D converters and they are located closer to each pixel. If you are having trouble with the difference between the two How Stuff Works has a decent explaination. If you are looking for a vendor or want to read some data sheets to get a better idea of the differences between High Speed and High Resolution than I suggest visiting Redlake , one of the many vendors that have products on the market. If you want a better explaination of the target Image Quality that digital is trying to achieve than head over to this guy's site. I guess I will make this my paragraph of website plugs. I couldn't resist linking to an article written by a Professor of the program that I graduated from. It is about capturing a picture of a bullet hitting an object using a conventional megapixel imager.
I am glad that
Bandwidth isn't a problem. Another misconception that I hope to alievate. With fiber you are not limited by the amount of data that you can transfer through the cable, but by how you store the data once it is transferred. Now of course changing the data from light into electrical would cause a slow down. The reverse is also true. What someone should find out is the limitations of these converters. The only way we would see an advantage of using fiber was if we could finish developing new methods to store the data. I have read scientific columns on 3D optical storage techniques that might be applicable in the future. I think I got a bit off the track let me try and get back on.
The reason Bandwidth isn't a problem is because we don't have the capability to produce digital images at the same rate as with film technology. While it would be nice to have a 1024 x 1024 sensor running at 12K - 40K fps, it is not something that we can do currently.
So the question is what do you want to do with the high speed camera? How much important is Image Quality? How much do you want to spend on capturing the image data? See when it comes down to it, it all depends on the situation.
I am not quite sure why we are talking about high speed digital cameras in the first place. Maybe the person who wrote the article didn't research the equipment that this guy was using. I found his website and it says he is using film. Oh nevermind I reread it and he posed the question about why not use digital. I sure hope that I have answered that question!
Someone should brave the Japanese site linked off of the itworld site and find out the resolution of the 1 million fps Japanese camera. I bet it isn't very much.
/.................../ \\
Kinki university, I think i saw that movie 7 mon... oh, oops.
High Speed Imaging with an AGFA Consumer Grade Digital Camera
Well, For one thing nobody records at that resolution. As another reply stated, DV is 720x480.
Another problem with your simple calculation is that video is never stored as 32-bit color. That's totally unrealistic. The common way to store video is not RGB, but YUV. Because of the way the human visual system works, the color components (U,V) are typically stored at 1/4 the resolution of the luminance (Y), meaning that an 3*X pixel RGB image would be stored as a X+X/4+X/4=1.5X image in YUV, half the number of pixels.
More significant, though, is that fact that just about every digital image recording mechanism stores information compressed onto the storage media. This is true from consumer digital cameras to DV cameras to the Sony HDTV cameras Lucas used for Star Wars.
Consider what it means to take 12,000 frames per second. You're probably recording a single nearly-instantaneous event, or getting many images of a very fast event. In the former case, there will be a series of frames before the event in which nothing is going on, and the difference between the frames is close to zero, which compresses extremeley well with MPEG-style compression. Your data rate could be 1/100th of the uncompressed rate. When the event occurs, the instantaneous data rate goes up, but buffering can solve this, since it probably lasts a few frames.
In the latter case, recording a fast event at a fast framerate, is essentially the same as recording a normal-speed event at normal frame rates. In this domain as well MPEG-style compression is extremeley effective. At the maximum you would need 1/5th or 1/10th the uncompressed rate, but 1/100th is a pretty reasonable number given current technology.
The only challenge with realtime compression at this speed, of course, is sufficiently fast hardware. I think it could be done in parallel -- capture several GOPs worth of data (15-45 frames perhaps) and send it to a compressor, and then switch the buffer output to a new compressor, round-robin style.
In any case, video is usually stored at rates many factors smaller than the uncompressed rate. So if you change the variables of your equation to a more realistic resolution and color depth, then divide that number by 10 or 100, you'll have a more realistic data rate.
720(w)*480(h)*1.5(color)*12000(fps)= 6.2GB/s, divide by 100 for agressive compression but reasonable results = 600MB/s
Still too fast, but not completely unrealistic if you've got a healthy budget. ;-)
If I recall correctly, the first high-speed cameras involved spinning mirrors/prisms to take the pictures. How 'bout taking say, 100 CCD's from ordinary video cameras, arranging them in an arc with a spinning mirror to direct the image from one lens to each of the CCD's- they could even use ordinary MiniDV recorders- then capture your data and stitch them back together... 30 fps x 100 CCD's- 3000 fps?
The trick, of course, would be synching the CCD's and the mirror...
Just an idea...
They got two models, the HCC-1000(F) can capture at up to 6832 fps, store up to 32768 images and send at 200fps. The resolution is limited to 256x64 at this speed. The CMC-1300 is able to capture and transmit at 485 fps in realtime with 1280x1024 resolution. More details here
Ok ok ok ok I feel stupid now.
I divided 2^20 by 24 not by 3, heh.
make that 349525 frames with 1 megabyte of storage per pixel.
Quite frankly with that much storage space I would say store 64bits for the visible spectrum and use another 24 for the infrared spectrum, and if CCDs ever get advanced enough, another 16bits or so for the ultraviolet.
With the visible + infrared though, that is 11 bytes, or a mere 95325 frames per individual pixel, hehe.
Need help treating your acne? Come here!
Yep I built a electonic video camera that had megarhertz frame rates 8 years ago. I patented it too. Actually two different designs.
C.E.M. Strauss, "Synthetic Array Heterodyne Detection: A single Element Detector Acts As An Array", Optics Letters, Vol 19, No. 20, 1609(1994)
and
B.J. Cooke, A.E. Galbraith, B.E. Laubscher, C.E.M. Strauss, N.L. Olivias, Grubler, A.W. laser field Imaging through fourier Transform Hetrodyne, proc of SPIE, 3707, 390-408, (1999)
the problem with pixelated detectors is reading out the darn pixels fast enough. Normally this is done by some sort of bucket brigade across the ccd or some sort of serial memory access across a cmos array. very slow. And parallel access to an entire ray is absurdly complicated and expensive
In my approach I solved this problem by multiplexing all of the pixel signals onto the same single wire. Each pixel when activated creates an osciliory signal at a unique frequency. All of these are combined on a single wire out put (amplified by a single fast amplifier) and then the AC signal is digitized by a single fast digitizer and streamed to a hard disk. The frame rate is determined by the frequency separation between the pixels, so if the oscillation frequency is a megahertz then a frame can be resolved every microsecond. This process is continuos and can go on for as long as you have disk space.
the other cool feature is that the chip you do this on is a single pixel chip! not a pixelated array. the pixels come from painting the chip with a rainbow of light. for a 1-D example, imagine red light on the left edge and blue light on the right. when a reference signal comes in it beats with the light. the beat frequency that gets ouput is determined by where (left to right) the incoming beam hit.
of course the good news and the bad news is that this is intended for active remote sensing where one is illumunating a target with a single frequency laser. It does not work with ambient light (note the second articele referenced above will work with polychormatic light) . The good news is that the detection method is hetrodyne detection which has shot noise limited detection sensitivity even on a crappy photo detector. thus the system is capable of detecting a single photon of light.
Another cool feature is that one can do doppler detection with this too since any frequency shift in the target's reflected shifts the pixel frequency. This could be used for example the image bllod flowing in veins, find moving objects in noisy scenes (e.g. submarines, air planes) or any number of flow imaging concepts. The heterodyne detection means its sensitive enough to do at very long distances (say space), or to use it for imaging through very dense media (for example, imaging through the side of a vein or through breast or brain tissue.
A description of how it works in stilted patent language can be read on line here
I was thinking about this the other day. I was using kazaa and happened to come accross a very startling video(quicktime rm slowmotion).
According to several sources(1, 2, 3), this one may actually be for real.
So I was thinking, if these guys really have found a way to disable things like sonic booms, and gforce/intertia...they could be flying around us all the time. But they are moving so fast we can't them.
Radar and other detective technologies would probably look at something like this as a system anomoly, and wouldn't report it.
But, if we had some of these 1M frames-per-second cameras just...filming our city skylines...we might we see some very interesting stuff.
The default settings were amusing - W95/98 would immediately choke and die as the VM system had no hope of keeping up with the screwy allocation setup from the acquisition program.
There are tricks you can perform to use a CCD in a non-standard fashion to get a reading faster than is the norm in photography - but it requires post-processing to figure out what you've got.
That digital camera can record an event with a maximum duration of 0.000103 seconds, roughly a hundred-thousandth of a second. That film camera can record an event with a duration of 0.01 seconds - a hundreth of a second. So, what can you record in that time?
.45 slug (assuming 900fps speed) streaking 37.5 feet in one frame and normal NTSC video, 30 feet. On that film camera, the bullet would streak not quite an inch in one frame. On a single frame of that digital camera, the slug would streak 0.000012 inches and since they shoot a whopping 103 frames, you'd see the bullet move 0.0013 inches. In other words, it wouldn't even appear to move. Pretty impressive.
Normal movie film can record a
From an artistic point of view, the problem isn't which medium to develop...it's how to improve both technologies such that cost/energy/latency is not too different. I should have the freedom to choose the technology which best serves the intent of the piece free from those constraints. It could be film, it could be video. It really depends on how I want it to turn out in the end.
So more substance, less rant: here's how I think these technologies would be useful to end users, and thus what we should be thinking about here.
Video Tap: A major video breakthrough in the feature film making process was Jerry Lewis's video tap. This puts a prism or split field diopter in between the lens and the film plane, splitting it in two, one going to the film plane, the other going to a video camera. This is how a director is able to get immediate feedback on how the scene went (instead of waiting for the dailies the next night to see it). A high framerate video tap for high framerate film would be extremely handy. The quality wouldn't have to be great, it would just need fidelity to tell the director and cinematographer how well composed the take was, and making sure all the stuff thats supposed to be in the take are there...and nothing else (like a boom mic).
Internet/NLE: This also would help in modern, internetworked digital non-linear processes. This is where takes are digitized as they are shot (if not already doing initial capture in DV) and dropped into the timeline in a nonlinear edit suite (avid, cinerella, final cut pro) whos project files are shared in an internetworked data store (film crews on other ends of the world, and the CG shop instantly are able to see their shot in the context of the other units shots...in realtime) via a 3 point edit. Even with a film process, the tap could digitize the footage and insert it into the timeline...the print of the footage could be later scanned and conformed to the timeline. Very handy. So this ties into the throughput problem. You have to consider that the bottleneck isn't CCD voltage intervals, cache tomfoolery or writing to a non-volatile medium. It could be a crappy ADSL connection or satellite uplink set up by people who scarcely understand how that stuff works.
Noise and heat: One of the banes of film making and one of the big advantages of digital video is the noise that all those ratchet/crank/shutter type mechanisms in a camera create. A lot of the sound work in a film is dealing with the noise from the camera. Sometimes, the sound is recorded later after discarding the sound from the set wholesale. Now, in order for a cmos imager to be effective at these speeds, we'll need to keep it cool. Heat is more likely to degrade throughput than buffer speed or size. Hence, we're going to need to build hardware to cool the cmos. That hardware is likely going to be more exotic than the cmos, take more energy than the motor for a high speed film device and potentially create a lot of noise on it's own. So the advantages of the high speed DV cam over film are only possible if the apparatus that supports the camera don't reintroduce the same problems on an equal or greater scale than existed in film.
Personally, I feel that the single greatest and most useful application of this technology, from a creative standpoint is the high speed video tap. It would liberate crews from the burden of dailies and integrate high speed footage into modern production processes.
For non-creative uses (scientific/research), this technology can free users from the latent and toxic nature of film processing infrastructure.
"Let him go, Ralph. He knows what he's doing." --Otto Mann (simpsons)
You're right about commercial video using much less than the maximum bandwidth, but that's taking advantage of the weaknesses in the human visual system. I would imagine that for most applications where a 12000fps camera is needed there is a greater need to capture each image as accurately as possible. In other words, you would want as much resolution as possible, both in number of pixels, and in sensitivity.
For 35 Gbytes/sec (280 Gbit), you'd need 280 gigE interconnects, and that's assuming you can perfectly divide up the data amongst them in realtime with no performance hit.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Note that he said 35 Gbytes/s. THat's 280 Gbps. Even 10GigE would be woefully inadequate. Hell even 100GigE would just barely cut it. You'd need terabit ethernet to do it properly.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
I'd like to see the sonoluminence bubble.. Maybe some new insights could be gained from analyzing how the bubble actually bursts.
and presumably, from the web site , they've gone to significant trouble to build a camera that produces the sort of images cinematographers expect, can mount the lenses they use in the film industry, can be easily transported to a film location, etc.
I used to work in a lab that used a camera that could shoot a sequence of images at 2 million frames/second on a strip of 35mm film. At the time these cost over a quarter million dollars. They're probably even more expensive now. Neat stuff, I designed the q-switching system to pulse a ruby laser to provide illumination for it. Never got to touch the camera, they sent a technician off for a week of training to run it and basically, no one else went near it.
Lots of people doing high-speed technical and scientific photography have switched to digital systems where smaller frame rates or less resolution will still do the job. There are still plenty of applications for film in high-speed photography though.
foog
All image capture is analog. It can be electronic (CCDs) or chemical (film), but there's always an element that "charges up" as it's hit by photons.
Compared to film, CCDs are extremely low-res (top quality 35 mm film has resolution equivalent to a 50 megapixel CCD) but, more importantly, they're slow. At very short exposure times, CCDs have so much noise that the final result is useless. The problem isn't the transfer rate, it's the time the CCDs take to "charge up" to meaningful values.
There is one alternative: use very large CCDs. The larger the CCD, the more light hits it, and the faster it can charge. But larger CCDs are more expensive and require special lenses.
Recording directly to digital does have one big advantage: you don't have to pay for the film. But the CCDs simply aren't up to film quality yet (and probably won't be for another 5 years or so). So the solution is simple: shoot on film, then digitise it.
RMN
~~~
There is an Astronomy project called Ultracam that uses special CCDs to capture astronomical events at highspeed.
Interestingly the computer interface that they use for the special CCDs uses Linux.
I am sure that you can get an idea of what is involved from Ultracam and use it in other real world applications (patents not withstanding).
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
Motion *starts* to look fluid above 24 fps, but some sampling and judder artifacts are still detectable by the eye/brain up to around 130 fps. Action sports (basketball, hocky, etc.) are rarely filmed at just 25 fps because the either the blur or the sampling artifacts are quite visible. Film directors have to be very careful with the shutter speed and editing of actions scenes in 24 fps movies because of this. 60 field per second video is noticeably better for sports in terms of motion artifacts.
I can think of one good reason why this isnt a good idea. As still digital cameras push the limits of how many megapixles they can fit into an image some profesionals are noticing an interesting problem. at a certain point, adding more resolution to a camera actualy decreases the image quality. THat's because when you decrease the size of the sensor which records the data for a pixel in a camera you decrease the amount of light that will hit that sensor.
This means that the signal to noise ratio for each sensor goes up. At 3 megapixels you wont see any degredation from this but as the resolution increases youre going to see more and more loss of acuracy and less acurate images. now this is for a camera which takes photo's at the equivalent of 50 ISO (1/50th of a second) if you want a camera that takes images at 12000 images per second that means each image has to be captured in about 1/36000th of a second, or 720 times faster, or 1/720 of the light will hit each pixel. inorder to maintain acuracy at that speed youre going to have to drop down the resolution to 4000 pixels per image (100x40?) inorder to maintain image quality.
--aiee
I'm sure such a camera could be created, but it would probably be insanely expensive to produce.
SIGFAULT
The article mentions something about no longer needing computer animation to film something like a bullet in slow motion.
Maybe I'm painfully naive here, but I'm not sure how this adds value.
12,000 fps with a max of 120 frames = 1/10th of a second played back at 30 fps = 4 seconds of film.
Besides, I would think that setting up the physical effect would (by now) be much more costly than doing it in CG.
I *can* understand how this might benefit us by being able to capture fast events (like some electrical/light or celestial phenomena, etc.) in more detail in order to understand them better, but I fail to see a justifiable cost/benefit ratio for the filmmaker....
moto411.com
So what do you do with the wasted film all 10 miles of it.
%s/Slashdot/google/g
Search for high framerate digital cameras. Let the poor slashdotters get back to writing code.
(+1 Funny) only if I laugh out loud.
What about something like a small rotating drum that spun just fast enough so that for every frame you would have fresh CCD elements to take the picture.
I guess the real solution though is for companies to work on high-speed image capture, but I doubt it will happen for some time as video seems to be too wedded to the slow FPS we use right now.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
http://www.cordin.com/product%20sheets/510_550.htm
I used to work for this company. They use rotating mirror and sensors (or film) statically mounted around. As somebody already mentioned light is very precious resource for those speeds, and cameras are ususaly not designed to work with this small exposure time. Friend of mine developed digital network sensor that can capture ultra fast events (10 ns exposure time, best if used with intensifier, of course). It's actually has been featured on slashdot before (linux inside, sure).
I haven't been keeping up with Myrinet... until they license their design to other manufacturers and/or drop their prices significantly, I'm not interested. If I wanted to be locked into a product built by only one company, I would have bought a Cray or SGI in the first place.
Switching to film in this instance is a no brainer guys, it runs a long the lines of "simplicity is beauty"
In other words, your looking for a kludge when there is no need for one - at all, the film does it, it does it better then digital (a point of light in the sky, i.e. a star or astroid is not the same as a car crashing into a wall or a bullet piercing glass) the film does it waaaay cheaper and better then you could possibly duplicate it with digital right now, so why bother? Because you might be able to? Someday, maybe.
I spent 3 years at the U of Minnesota's college of art and design, studying film - all aspects of it. Film, simply put, has a quality that digital can not touch, it holds life, digital, mean while, looks, feels and tastes artificial. Not to mention that there is no where near the depth of field in digital right now as opposed to real film.
To put this another way, if I choose to scan a 35 mm print for reproduction (instead of going back to the darkroom) to even get close to the quality of that darkroom print I must scan at a minimum of 600X600 dpi, sometimes (my relisys scanner can do realtime 9000 dpi- not software interpolation) higher- for an 8x10 print, this means (equivalent of one frame, if you will) a file of between 80 and 120 MB - go ahead and do that at 12,000 FPS, aint gonna happen in this lifetime.
Don't believe me ? Then ask your self why high end Photography isn't done digitally. Digital pics are only used to set the shots up - not for the real thing.
One further point - if your studying the impact of a bullet on this years replacement for kevlar, or what happens when a 80mm round hits an abrahms tank, you not only NEED SUPER HI RES, but you sure as hell don't want to look at it at 128x128 - thats what an instamatic from kodak used.
Problem here is, none of you know anything about film.
Mechanically inclined.
When was the last time you even heard that phrase? We live in a physical world. A mechanical device is a perfectly acceptable solution to a problem. Not everything needs to be done with software. Just look at the guy's level of disappointment. "But there has to be a way to do this with electronics! Electronics are always better than mechanics, aren't they? It's impossible for mechanics to do something electronics cannot, ins't it? Hello?"
And Cliff's additional writeup is no help either. The reason the video in the example he found can only played back at 103fps is fully explained in the link he provides (and apparently didn't bother to read). Also, the 12,000fps film camera that got everyone talking in the first place not the first of its kind. High-speed film cameras have been around for decades. The real kicker is Cliff's silly statement at the end, which makes it sound as though an electronic high-speed camera would be the first high-speed camera ever. He says, "What visual mischief could you aspiring photographers get into with such a camera?" Gee, I dunno Cliff, how about the exact same things people have been doing with high speed film cameras for the past 50 years, eh?
Sheesh. The world goes beyond the bits in a CPU. Turn off the computer and take a look around at the tangible, physical world.
Free Hans!
I worked on a High-Speed Video digital video system for Kay Elemetrics Corp. about a year or 2 ago. We used a camera system from Redlake Imaging. that allowed us to capture black and white images at 2000 frames per second. Resolution was limited to something like 160x120 but clarity was pretty good. We put a lens and an endoscope on the end of the camera and use it with a xenon light source to view movement of the larynx. It's good enough to caputre them in real time but total recording time was about 2 seconds. The images were dumped down a high-speed link to Redlake's PCI board with some ultra-high speed and ultra-expensive RAM onboard. After capture the images were slowly loaded down to the computer for storage as an AVI. The system sells for around 50,000 dollars (U.S.).
As people have mentioned, the problems are the exreme transfer rates necessary and the huge storage requriements. For our puproses, compression is not a solution because the medical community will not tolerate any loss of image quality.
Over at Micron Technology in the imaging department we are working on the next generation of digital imaging sensors. All the processes are CMOS based instead of CCD.
Of particular interest to high frame rates might be the MI-MV13, Micron Imaging - Machine Vision 1.3Mega Pixel CMOS digital image sensor. This particular sensor can do 500fps at 1.3Mega pixel but can also be windowed to do for example 4000 fps at 1280 x 128.
Bandwidth.
Pixel Depth.
Image Dimensions.
Bitch, bitch, bitch, bitch, bitch. To quote someone who dearly needs to be heeded in this case (Dennis Leary), "Shut the fuck up, NEXT!" I've heard enough crap, why don't we just call up Nikon and ask them for one of their explosive imaging cameras? If I remember my Guinness Book of World Records, that unit is a digital camera performing in the MILLIONS of frames per second! 12,000? Feh!
Gee, how about a simple Google search, even? Let's try that, shall we (since the Guinness world record site SUCKS!):
- "Fastest Camera" search
- "Ultrahigh-speed Imaging" search
.PDF in that first hit -- it's from "The Industrial Physicist", and has some nice info on a "gated still-video camera." A quote:
Another point I quickly found is that high speed (million-plus FPS) imagery has been around since the late 80s. Most of it's digital. (Imagine that.) You can thank the US military for funding that.First 3 links are about the same camera! A half-million dollars, 200 million frames per second.
Grab the
- "Multisensor, ultrahigh-speed electronic
imaging systems (such as that shown in Figure
1) are capable of recording sequences of
discrete images at frame rates of up to 100
million pictures per second. They incorporate
compact, intensified charge coupled
device (CCD) modules that exhibit virtually
no geometric distortion or intensity variation
and provide the user with digital images that can be analyzed using a personal computer."
Oh, one other thing: The article is from December 1997 when Pentium IIs were hot stuff, and you counted yourself lucky to have 64 MB of RAM and a 9.1 GB F/W SCSI-2 hard drive!"...America's great minds of today, teaching America's great minds of tomorrow. Poor bastards." -- A Beautiful Min
You are correct if you play it back at the same speed that you recorded it at.
If you are trying to show something like a bullet leaving a gun you will slow down the playback...
The benefit of converting to this Y'CbCr colorspace is that you can get cheap, easy compression by simply subsampling the 2 color-difference channels, Cb and Cr, and humans will probably not notice.
Now lets assume that your "healthy budget" means "professional" and not "consumer"... That 1/4 chroma resolution implies a 4:1:1 or 4:2:0 sampling format which is fine for consumer level products like DV and DVDs, but any professional-level hardware will use at least 4:2:2, bringing you up to 16bpp.
Let's try that calculation again:
720(w)*480(h)*16(color)*12000(fps)= 66.4 gigabits per second.
Now for those of you who want to compress this monsterous stream with a beowulf cluster, I'd like you to show me one that can suck a 66.4 Gbps data stream out of a camera. :) right.
That leaves us with the only option of compressing in the camera hardware as the previous poster suggested with an array of encoders, each working on 1 GOP. Assuming we use realtime hardware encoders, we'll need about 401 of them: 12000(camera fps)/(30000/1001)(NTSC fps) = 400.4. I'd recommend setting the 401 encoders to produce 5Mbps MPEG-2 streams to achieve a decent quality. That gives us about 2 Gbps of MPEG-2 output.
BTW, to hold a 30-frame GOP in memory for each encoder while they encode, we'll need almost 8GB of RAM: 720(w)*480(h)*2(color)*8(GOP)*401(encoders) = 7.74GB (Let's try 8-frame GOPs for 2GB of RAM)
To store that 2Gbps video stream, we'll need a single SCSI Ultra320 hard drive. (not bad)
Now go build it! :)
How about optical splitters leading to independent concurrently running cameras whose frame capture timings are slightly askew, so that the frame rates of the individual cameras are insignificant (if you have enough cameras and can tune their individual timing to properly interleave with one another). Furthermore, each camera then leads to its own digital storage medium, allowing for a natural dispersal of the bandwidth during capture and interleaving of the frames later.
Though this requires no moving parts, optical splitters do split the intensity of light in each branch... your solution for mechanized movement of the light from one camera to the next may be best.
... beowu... oh, hang on. Nevermind then.
Small Black Dog
See it yourself here. Not so good resolution thought.
i guess you will need to store it differently.
since you are talking about ntsc video. this is film quality. why do you think that film has not yet been replaced as of the moment?
film is uncompressed. film has a resolution of 4096x4096 pixels.
so if you do the math before:
4096 * 4096 * 1.5 * 12000 = 301,989,888,000 bytes
if you are not going to remove any information and treat it as an rgb image:
4096 * 4096 * 4 * 12000 = 805,306,368,000 bytes
it will be very difficult to get that much information with the current conventional hardware compared to creating a film capture with a mirror/prism in the middle rotating, which is much more affordable.
i guess you can just transfer the film afterwards to digital format using lots of film scanners. this will still be affordable compared to building a system that would withstand that data transfer rates.
if you are going for the 300gbytes, you will need around 1,500 2Gb FC disk array to capture that amount of data (that is if each array will sustain 2Gb/sec.) and how are you going to distribute the data to the array in the first place?
some thoughts...
Live your life each day as if it was your last.
You record at 12,000 fps to playback at 24fps to view high-speed events, such as bullet leaving a gun or the instance of a fracture in glass before it breaks upon an impact, in remarkable and interesting detail. It's a matter of examination of events too fast for the human eye to see. You'll see some of this used in upcoming cinema but the real benefits are not in entertainment, but in science. Discovery channel had some footage on this. Very impressive.