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The Technology Behind the Magic Yellow Line
CurtMonash writes "Fandome offers a fascinating video explaining how the first-down line on football broadcasts actually works. Evidently, theres a lot of processing both to calculate the exact location being photographed on the field — including optical sensors and two steps of encoding — and to draw a line in exactly the right place onscreen. For those who don't want to watch the whole video, highlights are here."
Hmmm... A new trend? No longer reading 'have not RTFA' but 'have not Viewed TFA'? /. coming to.
Dear oh dear, what is
I already knew in pretty significant detail how all this works, but there was a lot of additional information in the video that never made it to the PR-sanitized behind-the-scenes descriptions of the technology.
Plus, you get to see the ugly UI that appears to have been built as an afterthought - just like the UI of all the other industrial television software I've operated.
Would be a field that uses clear/transparent turf. and all colors on the field are defined by lights under it. The white in the 10/20/30... could be done dynamically, the end zones could be designed dynamically and relit, heck, you could switch from a green field to Boise State's blue.
This could be used to make the same field a football field, soccer field, lacrosse, field hockey... all without the the clutter of all the lines on one field.
This might be tricky with turf technology currently, but I feel like a first technology to do this might be a basketball court (lights for basketball, volleyball, etc)...
It probably isn't feasible, but would be interesting.
Yeah - it is one guy and as long as he doesn't put on an annoyingly green tie - it all just works. It is actually amazing how much technology is behind simple video effects done seamlessly. I thought it was funny when Forest Gump won the oscar for special effects - everyone was like... that isn't a special effects movie... I was like - that is the point
I have mod points and I am not afraid to use them
are the ones on the platforms at train stations. (In QLD anyway) The closest thing we have to this in sports around here is either during swimming, or between balls during a test match, when the commentators are bored and start drawing lines all over my TV.
The camera can zoom out to a wide field view and the computer can scan for the yard lines (maybe taking some time as players walk around) to calibrate the perspective. Do it again at a midway and zoomed in position to get the zoom calibration. Thereafter, the pan, tilt, and zoom sensors can guide computer to where to draw the line. And if the yard markers do happen to be in view with high confidence, that can refine the calibration at any time.
now we need to go OSS in diesel cars
The yellow line is one thing, but TV sports have become the forefront for real-time image manipulation, mostly for the purpose of inserting advertisements.
Personally I hate that trend. Luckily for me, pro sports was already becoming so infested with commercialism that I stopped being interested after adolescence.
But how long before this kind of b.s. makes it into non-sports television? "The Obama inaugural, brought to you on the capitol mall by ..."
I watched the game tonight, and surprisingly, I was trying to figure out how I would do it. Yes, nerdiness has infected us all.
I thought Football was a game played with your feet! What the article discusses is a bastardised form of Rugby.
TFS made it sound like the video was an entire documentary that was going to eat at 30 minutes out of my morning. So yes, in the interests of saving time I clicked the highlights link, only to find that it would have taken longer to read the highlights than it would have to watch the video!
Seriously, three and a half minutes? Do we at Slashdot have that short an attention span that we need highlig... OH LOOK A BIRD!
That's true, but I was always more fascinated by the stuff they did for NASCAR. Not only do they use on-screen tech, but they also make use of GPS to do those fancy graphics showing info on the cars while they're moving on the road.
There was an article about this particular tech NASCAR uses in some magazine, but I can not for the life of me remember it, nor can I find any videos demonstrating it...
Random Thoughts From A Diseased Mind (Not For Dummies)
The parent post shows the precise reason to move to the not-so-brain-dead SI units. First of all, when someone writes "football" on slashdot. Is he referring to what is commonly known as "football" all over the world, i.e. "soccer" or what is commonly referred to all over the world as "american football"?
Secondly, 360ft by 160ft with 1in resolution suddenly became 4320 by 1920? How do you calculate that? Well, by multiplying with magic numbers (in per ft, ft per yard, cow length per farmer fatness etc).
In SI units, it would be 110m by 55m. I'd say the resolution would need to be at least 1cm (when a line on the field is about 10cm [4in], you'll need at least a tenth of that for nice rounded lines for some sports).
110m by 55m equals 11000cm by 5500cm.
Hence, you'd need 11000 by 5500. You need not know magic numbers. You need not multiply with any non-power-of-ten number.
How is this not easier, more logic, quicker for mental calculation?
I'm sure the parent poster had to use some kind of calculator (or a google query) to find out what resolution would be needed.
Paaaaaathetic.
Even by using a fraction (or multiple) of 1cm, you'd still go through cm and then add/divide. You do this easily by simple mental math.
The britts could do it, now it's you turn, Yanks.
http://www.youtube.com/watch?v=Vh9af_gXxlM&fmt=18
I have always been amazed at the NASCAR broadcasts... if only the high-tech world of Formula-1 could catch up with these good 'ol boys!
By the way, how do soccer stadiums paint dynamic ads next to the field, visible on TV?
... All that technology applied to paint a yellow line in a completely arbitrary position. The rules need to be changed so that the location of the ball touching the ground is the location of the line. Also, the ball should have some kind of RFID chip in it, and the entire field should be built on top of a fine mesh of RFID sensors. Until then the location of the line is subject to too much human error, and as a result completely arbitrarily placed anyway.
They didn't say how it was calibrated but let's face it, there's two guys sat there constantly tweaking it so I'm pretty sure the initial pre-match calibration will be done manually.
The only clever part is the camera tracking and perspective correction.
And the interesting part is how they transmit the data round, switching between audio, over the hidden TV lines, etc.
No sig today...
Always wondered how they did that but never bothered to look it up. I thought they were doing surface analysis and then extracting the numbers, that would be a really hard problem, looks like they found a similar solution. I guess they must leave the cameras in place as I'd suspect it would be a real pain if you moved the camera after each game and then had to recalibrate.
I already know how the magic line on TV works. When I first read the title to this article I thought you where talking about that yellow line at the grocery store that keeps the shopping carts from leaving the parking lot.
Uncle Mantis
This guy reminds me of Jack Hanna for some reason.
its a 3:30 minute video...do you really need highlights of a 3:30 minute video?
I'd have liked to see actual examples of the colour failing to draw on certain surfaces, etc
If you really like fancy 3D computer vision and graphics techniques in sports broadcasting, check out the amazing work of http://www.liberovision.com
Or space shuttle's HUD.
Yet they need a shitload of computers (a server farm WTF !?) and several people to make this work ?
Sure, it's cute that they don't draw the line when the background's not green, but it's hardly "amazing science" or anything.
the lack of a oval track means you would need a lot more cameras. But yea, theres also a lot of money in F1 so that shouldn't be a problem. The tv broadcast are lacking. I have also though there would be market for multi angle dvds at the end of the season too, but the available footage is on the drab side.
If your sport requires special on-screen aids to understand what's happening it's probably overdue for a rethink.
That's like saying if your software requires a flashy box and a slick interface, it's probably due for a re-coding.
These TV tricks are pure marketing, designed to extend the appeal of the game to the very casual observer. Football has been extraordinarily successful at every level for decades, and clearly does not need "on screen aids" to be understood.
This is not the first example of such "dumbing down" of pro TV sportscasts. You may remember Fox Sports' "streaking puck" experiment a few seasons back during their NHL broadcasts. That proved a dismal failure (although it was a technical wonder at the time); the first down line-generation has proven a much more successful gimmick.
No, you know your sport is due for a re-think when its fans riot in the streets and generate massive amounts of property damage. Violence and Premature Death are civilization's long-established barometers of failure.
This is all fascinating and everything but the masses really want to know what ever happened to that halo they used to have around the puck in NHL games?
I'm usually good with technology but I don't get football analogies. Could someone explain the technology behind this magic yellow line with a car analogy?
"A witty saying proves nothing." - Voltaire
And it's always fun when it gets a little glitchy. I love seeing the driver/car marker pointing to some empty space off the track. Probably doesn't happen as much anymore, but it seemed to happen fairly regularly when I'd watch some races with a friend 3 or 4 years ago.
This guy's the limit!
And it was awesome that Pixar reproduced these glitches in the opening scenes Cars.
And that's on top of $100k hardware, $25k/year support agreement, and per-seat licensing for the admin and client portions.
So yes, you're absolutely right.
Boot Windows, Linux, and ESX over the network for free.
Perhaps you could link the damn video, instead of (as usual) a link to the blog that links to the video? :(
http://www.fandome.com/video/107610/The-Mystery-of-the-Yellow-Line/
-Styopa
If it were replaced with FOSS, it probably wouldn't have a UI at all, considering the tiny userbase.
I completely forgot about that. I should watch that movie again sometime.
This guy's the limit!
It's easy to show the cars moving around on the road in Nascar; they only go around in a big circle!
There are a couple of NASCAR races that take place on SCCA road courses.
I was watching a Ravens regular season game (I think) and for a couple seconds we had the view of the computer's field: black background colored lines. I realized that indeed, there was a digital 3D field that was lined up to match the camera's view. After that, it is a simple matter of using the actual camera as a player in a game with pan and tilt of the actual camera to match the virtual camera. Then, its just a projection of a line with color keying in the composite video.
Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
Last time I was driving in England/Scotland/Wales, *ALL* of the road signs were show distances and speed limits in miles and MPH.
Web sites like these seem to indicate that nothing has changed in that regard.
In other words, the UK is hardly a good example of a country which has converted to metric measures. Perhaps Canada would be a better choice?
Mainframe/UNIX Bit Twiddler and long time Windows/Linux Hobbyist.
The Theorem Theorem: If If, Then Then.
And really, if you've lived with non-metric units all your life, it is easy. I have no problem knowing what size and 8 oz tenderloin or 16oz strip steak is or how big it is. I'd be completely lost trying to, off the top of my head...buy or cook with metric units. When I college in a lab, sure, no problem in doing chemistry experiments in metric, but, that isn't real every day life stuff.
I know how to dress when it is 72F outside. I'd have no clue what to dress for at something like 32C (random temp)...
A handy guide to converting to metric.
the great taste of Charleston Chew?
try eliminating "sport" from your search terms.
Not being a sports fan, I don't see much of this stuff, but I once visited the company in Silicon Valley that makes the gear. The "yellow line" is one of the easier applications. It's basically a camera with encoders driving a fairly simple video processor. Calibration is manual; there's a setup display that shows the normal lines of a football field, and someone aligns the corners to match the real image from the camera. When the generated image matches the real one, the system is in alignment.
That's 1998 technology. The newer systems have gone way beyond that. Ads on billboards are sometimes replaced using the same system. Ads you see on the air may not be what people in the stadium are seeing. There's player tracking, ball tracking, the "virtual strike zone" for baseball, GPS-based tracking for NASCAR, and virtual billboard insertion into everything.
Magink has an E-ink system used by billboards with a 9mm resolution. Curved lines would be a little pixelated, and you wouldn't be able to replicate wood grain, but it would be enough resolution for the the sake of the game, and could do some interesting things during half-time. The reflective nature of E-Ink would make it much better suited for this project than an emissive display, and if it is cheap enough for a billboard, it is definitely cheap enough for a court (especially since it would likely be used as a billboard part of the time). Most indoor courts get their surface properties from varnish/wax, not the flooring material so that wouldn't be a problem either.
My main concerns would be structural support (can this stuff take being pounded on by 200 pound athletes), and how you would replace bad cells once you put the varnish surface over it. Plus something like this would become out-of-date almost as soon as you finished building it.
Did I hear a fax/dial-up modem connection in that video? LOL.
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
I'm with you... sometimes too much technology can just ruin the game for viewers. Keep it simple, the glowing line is kind of helpful but really, after watching a few games and learning the rules, I think I can figure it out for myself. And glowing grass? Maybe an advertiser's dream come true, but bad for all the reasons you mentioned.
Any hockey fans remember that awful glowing puck the NHL tried out 10 years ago, because apparently some people had trouble following the puck? Here's a hint: look where the action is, and there you will find the puck. As well, the camera operators are skilled professionals - trust that they will be centred on it, unless the clock is stopped.
The puck's tech is actually kind of cool, although I remember the way it left streaks across the ice looked like someone set "mouse trails" to maximum on a computer desktop.
I'm a big fan of metric, but I can still see a lot of sense on imperial units, even though I don't use them a lot except for the conventions that have survived like time measurement. There are some really weird units, but imperial's major strength is that its most common units tend to be ones that are handy for tasks that people deal with from day to day. 12's a great number because it divides by so many different whole numbers (1, 2, 3, 4, 6, 12). If you have 12 of something, it'll be very versatile for being evenly split up in small groups of many sizes. This is why so many things come in 12s or similar multiples.
I'm not an expert on any of this stuff, but I'd guess that the whole '12' thing is probably also why days are historically divided into 24 hours. It makes it really easy to divide a day into discrete blocks when doing basic mathematics, which is the kind of maths most people do. Divisions of 60 are just another convenient multiple.
As for 12 hour clock-faces, it's probably just much easier to read a clock face that's divided into 12 than into 24 because the gaps between the numbers on a 12 hour clock are bigger. Even if the hands go around twice in a day, you'd nearly always be able to figure out the time based on what you already know about the day so far. There are still some annoyingly ambiguous terms that are common, like 'midnight' being used to describe both the beginning and end of a day. (If someone says 'midnight Saturday', I don't know for sure what they actually mean.)
Circles are probably divided into 360 degrees because it's a very divisible number that's very close to the number of days in a year. Every night the sky and everything in it will have moved about 1/360th of a circle from where it was at the same time the previous night, before returning to where it started. If you don't have a lot of accurate measuring and construction equipment, it's still easy to divide a circle into 360 parts (a few straight lines are easily derivable locations). If you make such a circle and line it up with things in the sky, you could figure out the day of the year relatively easily to quite an accurate amount.
There is such a thing as Metric Time, but it never really took off with the rest of the metric system.
Personally I still think it's important to have systems that work in people's heads for everyday tasks, just because people aren't computers. Metric's a nice compromise for me. I've wondered for a while what it might be like if the principles of the metric system were applied to base 12 instead of base 10. Maybe you're right, and 16 would be a better option just because we have so many computers around, but as long as most people aren't directly dealing with computer implementation, they're most likely to fall back to a number that's most directly obviously useful to them. 12 is a smaller number than 16 and it divides by more whole numbers, so it wins on two counts.
Yea.. I loved that, especially as I was the one who wrote a bunch of the RaceFX code, originally.
That was a very complex system involving hardware in -many- locations (each car, various points in the stadium, in the TV compound, etc. etc). It required a tractor-trailer's worth of stuff each week (several miles of cable can take some space too :) ).
It was stressful (consider having to recompile your application during a commercial break because the producer/director don't like something)..., but rewarding!
Please, someone shoot this idea down - why not just do it with infrared lights on the sidelines or something similar? All you need is some focused, non-visible light broadcast at field level and you could paint that visible using a chroma-key-like system. Calculating the angles of this and the deflection of the field, etc, etc seems far more complicated than it has to be...
What would cure you is the SI unit of storage space. All you have to do is measure disk sizes in kibibytes and you're good to go. It's kibi from kilo-binary and Mebi for megabinary. Using the SI units, if you have a 200Mebibyte disk then you know it's 200*2^20 bytes rather than trying to guess whether they actually meant 200*1e6 bytes.
you'd get modded flamebait if any nascar fans could figure out how to use the internet