Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Ask Slashdot: Image Recognition For Race Timing?

timothy posted more than 2 years ago | from the show-your-work dept.

Open Source 170

First time accepted submitter int2str writes "Autocross is a form of motorsports practiced in the U.S. and around the world where car enthusiasts explore the capabilities of their car in an open parking lot or similar suited area. It's point-to-point racing (not closed circuit). Most of these events are organized by car clubs and volunteers. Timing is usually done with a form of detection beam at start and finish that gets interrupted by the car crossing the beam. Many commercial systems are available. All of these system require the operator to enter the car's number or ID and requires the cars finishing in the order they started. So if one car is not able to finish, the operator has to intervene, or timing is broken. For closed circuit racing, transponder systems are available to address this problem. But such systems require sensor loops in the track or overhead (bridge setup) and the transponders are expensive. Do you think it would be possible to design a timing system using off-the-shelf parts and open source solutions to uniquely distinguish about 100 participating vehicles and time them from a start to a finish point, independently of their finishing order?" Read below for some more details:int2str continues: "My initial idea would be:

  • Use (web-?)cameras at each end that feed into a Linux based notebook (USB/Ethernet).
  • Start recoding still images as fast as possible when motion is detected
  • Identify unique shape, numbers, barcode, qr code or similar in the images, that have been attached using a magnet to the vehicle's door.

Difficulties to overcome:

  • Camera with high enough shutter speed to get recognizable image of vehicle traveling 30-60mph
  • Quickly and accurately identify a unique symbol or shape

So far I've started looking into OpenCV as a possible tool for image recognition, but have not been able to find a capture solution. Does anybody have experience with something like this? The solution would be open source and well documented as to benefit the many car clubs around the country and the world."

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered


Seems simple (2)

pspahn (1175617) | more than 2 years ago | (#37875064)

  • Timer on board vehicle
  • Timer starts as it leaves starting line
  • Timer stops as it crosses finish line
  • Timer info is sent to controller

What exactly is the problem here?

Re:Seems simple (-1, Troll)

Anonymous Coward | more than 2 years ago | (#37875130)

Race timing? Is that like the way whites outperform blacks every single time you compare them? It does not matter. It can be social status, economic achievement educational achievement, IQ, rate of out of wedlock children, drug abuse, spousal abuse, alcoholism, violent crime, ability to sustain a single prosperous nation... black people just fucking suck. Objectively. They suck. They embrace a anti-achievement culture where getting ahead means you're an Uncle Tom and we can't have that. Then they cry and scream about how nothing is their fault including their self-destruction. It's all Whitey's fault. Yeah. Nevermind other groups like Jews and Chinese and Native Americans have also endured real racism and don't have these problems to this degree.

Bunch of niggers.

Re:Seems simple (0)

Anonymous Coward | more than 2 years ago | (#37875144)

The entrance cost to an autocross is $15-$65 per car. That usually barely pays the fees the club endures to put the race on (insurance, lot rental, cones, safety gear, etc).

To put a reliable timer (accurate to .001) in each vehicle, at two exact points on the track, would be very difficult to do cost effectively.

I think a mix of the current timing system plus an RFID or image capture is a great idea.

Re:Seems simple (1)

Yaur (1069446) | more than 2 years ago | (#37875582)

RFID, maybe with a camera as backup, seems like the way to go.

Re:Seems simple (1)

SomePgmr (2021234) | more than 2 years ago | (#37876080)

Much (if not most) of kart, rc car and auto racing is timed using transponders (either active or passive) and a buried loop (antenna) at the start/finish. All crossings are time stamped by hardware there, and read into a db for race management and results. This method is also commonly used for marathons and such.

It makes for one authority on time, where multiple racers would have times relative to each other regardless of the accuracy of actual time at the device... which is set using buttons on the device, GPS, locally attached computer or with NTP.

Perhaps there's something unique about motocross that doesn't lend itself to the same systems everyone else uses... but otherwise, you nailed it.

Re:Seems simple (1)

fluffy99 (870997) | more than 2 years ago | (#37876766)

RFID, maybe with a camera as backup, seems like the way to go.

It certainly works for bike and running races. Last few races I attended had antenna beside the course and not a timing mat. Perhaps combining the RFID for the ID and a photosensor for more accurate timing.

Or for more low tech, a person at the start and finish keying in the numbers. Plenty of running races have hand held timers that the official just clicks the button (maybe trigger with photosensor instead) and keys the race tag number.

Re:Seems simple (0)

Anonymous Coward | more than 2 years ago | (#37875614)

The cost is amortized across all races. It's rented equipment. This seems the most reasonable solution. You have a trade off of accuracy or cost... you can't have both.

Re:Seems simple (0)

Anonymous Coward | more than 2 years ago | (#37875268)

Problem with that is that you're trusting the client instead of the server. Cheaply made MMO games should have taught you the downside to that.

Re:Seems simple (0)

Anonymous Coward | more than 2 years ago | (#37875298)

There are rules limiting how quickly cars can take back to back runs, and these are normal street cars, not race cars.

The event stopping as timer is switched from one car to another 5 times for each car * 200 cars is a big problem.

Re:Seems simple (2)

TubeSteak (669689) | more than 2 years ago | (#37875530)

What exactly is the problem here?

The problem is that your solution requires us to trust the client.
Not only should you never trust the client, you should assume the client is hostile and act accordingly.

Re:Seems simple (0)

Anonymous Coward | more than 2 years ago | (#37876430)

-john carmack circa quake 1 (they saw what happened to doom)

Re:Seems simple (1)

Reelin (2447528) | more than 2 years ago | (#37876636)

you should assume the client is hostile and act accordingly

And this line of reasoning is how Trusted Computing was born. Wait, you mean we're supposed to trust the client unless we have a good reason not to?!?

Re:Seems simple (1)

xtal (49134) | more than 2 years ago | (#37876026)

Detecting the finish line is one problem.

Detecting multiple cars crossing the finish line within a few ms is another problem.

Trusting the client is another issue.

Price is another..

Re:Seems simple (1)

JoeMerchant (803320) | more than 2 years ago | (#37876320)

Autocross generally charges $20ish as an entry fee... the timer onboard vehicle would raise the barrier to entry higher than most clubs would want (due to cost / complexity for newcomers.)

Reread the summary (1)

thegarbz (1787294) | more than 2 years ago | (#37876678)

  • Timer stops as it crosses finish line

What exactly is the problem here?

Was already mentioned in the summary question. Transponder location is the problem. You fall down on the detection of where the finish line is.

Predator software (0)

Anonymous Coward | more than 2 years ago | (#37875086)

The technology is definitely out there. Check out the following links.


simplify (1)

TheSHAD0W (258774) | more than 2 years ago | (#37875088)

Some large numbers on the sides or hood of the car would make image recognition, if not trivial, at least relatively simple.

Re:simplify (1)

JoeMerchant (803320) | more than 2 years ago | (#37876292)

Numbers on the cars are more or less standard, but are usually a mixture of different types, including shoe polish on the windows - OCR would be... challenging.

Most definitely (2)

Antisyzygy (1495469) | more than 2 years ago | (#37875118)

I worked in Face Recognition as a research assistant for my MS. I was part of a group designing a robust end-to-end system for the purposes of identifying people in a wide variety of conditions. This problem seems easier because you can assume that the cars will be in one location within one time frame, the camera is fixed and everything in your data set will cross this line unless they break down, they will have almost identical 3D structure (unlike the face), and you can expect some identifying marks on the front end that crosses the finish line. As long as you have some sort of identifying marks, you can use standard face/object recognition techniques to identify the vehicle. There are some pretty advanced algorithms out there. The best out there when I was actively working in face recognition was STASM and Pittpatt. Better yet, if you had some unique identifier expected at some part of the vehicle, you can easily make the problem much easier. For example, have each one use an infrared identification tag located in precisely the same spot relative to the build of the vehicle.

Re:Most definitely (0)

Anonymous Coward | more than 2 years ago | (#37876130)

I worked in Face Recognition as a research assistant for my MS. I was part of a group designing a robust end-to-end system for the purposes of identifying people in a wide variety of conditions.

It must be hard to write all that code with hooves.

Re:Most definitely (1)

Antisyzygy (1495469) | more than 2 years ago | (#37876190)

I suspect what you mean is that I am a demon because I sided with Teh 3vil |31g |3r0th3r. Technology != evil. Its how its applied that matters. There are legitimate uses for such technology, such as identifying a person who is trying to enter their home, or a person who is trying to access their bank account, or even to identify a person known to make bombs and blow people up who try to board airplanes. Its not necessary to be a luddite to avoid abuses of technology. Fix the system rather than oppress scientific development and innovation. You can band together with like minded people and force laws into existence that protect you from abuse, or you can just stop being apathetic and never allow such abusive laws to pass.

Re:Most definitely (1)

JoeMerchant (803320) | more than 2 years ago | (#37876302)

they will have almost identical 3D structure (unlike the face), and you can expect some identifying marks on the front end that crosses the finish line. As long as you have some sort of identifying marks, you can use standard face/object recognition techniques to identify the vehicle.

The cars in autocross are as (and usually more) varied as what you see on the street. In a field of 100 competitors, you might expect to see 5 or 6 participants with a particular make/model, for the most popular (e.g. 6 Miatas, 5 Neons, 4 Corvettes, 4 Mustangs, and a hodge podge of all kinds of cars from the last 40 years.)

Re:Most definitely (1)

Antisyzygy (1495469) | more than 2 years ago | (#37876324)

This is still more-or-less a significant domain reduction over the human face. If you weren't human you wouldn't be able to identify one face from another. Try identifying faces upside-down sometime in a split second. We are uniquely built to identify very small variations in the human face in upright position. I suspect the front end of a car would be much less difficult. For example, first classify what the make of the car is, then classify color, then classify markings. If you have a database of cars in the race you will find a match with high probability.

Re:Most definitely (1)

JoeMerchant (803320) | more than 2 years ago | (#37876418)

There is a practical issue with photographing the front (hard to protect the camera) - most timing equipment is located 30' to the side of the finish line (you can get closer at the start.)

Neck beards (-1)

Anonymous Coward | more than 2 years ago | (#37875136)

I hate neckbeards.

Barcodes (2)

GrahamCox (741991) | more than 2 years ago | (#37875138)

How about sticking a big barcode to the competition number panel and use a simple barcode scanner to ID the vehicle as the beam breaker is triggered?

Re:Barcodes (1)

Dan East (318230) | more than 2 years ago | (#37875270)

This is the cheapest / most versatile option, but you would use QR codes [wikipedia.org] or other 2D codes designed specifically for this kind of image scanning and not traditional 1D "barcodes". Issues to consider would be lighting, the camera's ability to capture clear images at whatever speed the vehicle is moving at, etc.

Re:Barcodes (1)

GrahamCox (741991) | more than 2 years ago | (#37875392)

Using QR Codes is still complicated compared to simple barcodes. You need a fast camera, image processing, etc. That might be acceptable of course. But a simple laser barcode scanner is cheap and effective, and simpler to interface. You can print the barcode for the competitor on a sheet of office paper and stick it to a side window with tape. Super-cheap and likely to work. There could be a problem ensuring that several vehicles arriving at once were able to be scanned (that may not be an issue for the sport, if vehicles are set off at timed intervals and don't tend to catch one another - not sure).

Re:Barcodes (1)

Anonymous Coward | more than 2 years ago | (#37875694)

I disagree that 2D barcodes are better for this than 1D - the OP said they only need to distinguish between ~100 vehicles, so you really don't need high data density. Plus, I think using a 1D code could help you get around the shutter-speed issue: if you turn the barcode so the stripes are horizontal and capture images across the start/finish lines, motion blur shouldn't affect your image capture. You would need to make sure you get the barcodes on each car positioned at the same height (relative to your cameras), and that the lighting is good enough (high contrast is the most important factor). Note that this system wouldn't work if you have cars finishing at the same time (but then, I don't see how the beam-blocking systems would figure out if two different cars are finishing at the same time).

I suggest looking into zbar (zbar.sourceforge.net). It's an open source barcode reading software, which has support for many different types of 1D and 2D codes. It comes with two example programs - one for static images, and one for webcams. I've never tried the webcam version, but the static image decoder works great.

For generating barcodes, check out:
There's a web-based front end for it, but with a little hacking on the Postscript version you can print out pretty much any kind of barcode in any format you want.

Re:Barcodes (1)

white_owl (134394) | more than 2 years ago | (#37875918)

I think Barcodes are a good idea, and as the grandparent of this comment mentions they could be on a fixed part of the car say the front right corner of the car. Magnetic signs would be reusable, although a white sheet of paper with blue tape holding it on would make it easy to find the barcode in an image. Then when the car trips a light beam at the start/finish line you can take one frame and the barcode will be approximately in the same location. I would argue in favor of 2d codes vs QR codes. If you use 2D barcodes so that the lines are horizontal, then the system could tolerate a fair amount of blur. Since you only need an identifying number for the car the ability of QR codes to code a good deal of data is not needed.

Re:Barcodes (1)

CityZen (464761) | more than 2 years ago | (#37876248)

Yes, you win. Note the two main ideas: 1) Use the existing beam breakers to get the timing down to whatever precision is needed.
2) Have the beam breaker also trigger the camera or whatever system is recording the bar code or other easily-machine-identifiable visual code.
The camera part doesn't need to be timing critical, in this setup, since the beam breaker system is dealing with that.
Of course, there's still the matter of writing a bit of software to tie everything together, but that should be pretty elementary.
(If you don't have an existing beam breaker timer system, then you could probably find something at instructables.com.)

RFID (1)

Anonymous Coward | more than 2 years ago | (#37875164)

There is already an outfit doing motorcycle road racing using RFID. it would work in this instance as well.

Re:RFID (1)

GameboyRMH (1153867) | more than 2 years ago | (#37875464)

I was going to suggest this. The stage rallies around here use optically triggered timing plus RFID for identification.

The autocross group is on an even smaller budget so we use a guy with a stopwatch and a clipboard. It's good enough.

You're overcomplicating it (3, Informative)

Uksi (68751) | more than 2 years ago | (#37875226)

I autocross and I've been thinking about the same problem. I even thought about writing my own free software and building plans for off-the-shelf/cheap-to-make transponders ($1200 for a wireless transmitter unit? jesus).

The problem is that if a car doesn't finish and misses the timing mark--the software shoudl just let you to fix it up. You should be able to say "this car didn't finish" (has a missing tick) or "ignore this tick" (some corner worker tripped the lights accidentally). Then it shoudl be able to just recalculate the times affected. It seems so simple to me, I am baffled that it hasn't been implemented.

All the cars starts in the same order, all the numbers are known at hte start time and cars never pass each other. So you have always same-sequence travel of cars. All you need to do is fix occassional lacks of ticks or extra ticks. No need to re-run the cars.

Re:You're overcomplicating it (0)

Anonymous Coward | more than 2 years ago | (#37876294)

I too am an autocrosser (and incidentally do timing as well). This could easily be solved with more intelligent timers, as the parent suggests. Take a look at how club racing does paper timing, a similar algorithm (but electronic) would allow for corrections after the fact.

Re:You're overcomplicating it (1)

JoeMerchant (803320) | more than 2 years ago | (#37876340)

I also autocross, and I think a practical solution would be to add a network camera to each electric eye installation, connect them wired or wireless to a notebook, and simply snap photos as the beam is broken. Keep timestamp records for each beam break event, assume everything is running normally, but also do a fairly simple color check on the car to verify that the assumed finish time event matches the start event. Display a series of thumbnails on the screen for each automatically determined start/finish pair, and if the system ever messes up, all the operator has to do is slide the finish photos to match the start photos - and the times will be calculated automatically (iPad would make a nice interface for the system...)

If you want to be lazy enough for the system to i.d. the cars exactly for you (and tabulate all the times with minimal operator intervention), I'd go to issuing QR (2D bar) code panels and add that to the software - but it will still fault occasionally and need human attention, and the other thing to consider is if fiddling with the bar codes is really less work than just babysitting the timer and hand entering the car numbers as they start.

Re:You're overcomplicating it (0)

Anonymous Coward | more than 2 years ago | (#37876660)

> All the cars starts in the same order, all the numbers are known at hte start time and cars never pass each other. So you have always same-sequence travel of cars. All you need to do is fix occassional lacks of ticks or extra ticks. No need to re-run the cars.

Sometimes cars do spin on track and others pass them. This breaks the sequence.

Use the best software (1)

jbeaupre (752124) | more than 2 years ago | (#37875264)

I'd suggest using the best software available: the human brain.

Version 1
Aim a camera at the finish line. Aimed to capture the racer's number and any other identifying information. Set the camera to be triggered by the interruption of an IR beam. Place a clock in the picture field.
During / after the race, find each racer's picture and record the time.

Version 2
Aim a video camera at the finish line.
Use a laser pointer as a finish line. Aim it at something white and make sure it is visible as a racer crosses
Put a clock in the field.
After the race, fast forward and write down the time each racer crossed.

As a bonus, you have photo evidence in case there is any dispute.

Re:Use the best software (1)

swalve (1980968) | more than 2 years ago | (#37875646)

I was going to suggest the same sort of thing. Two cameras in timesync with each other.

Re:Use the best software (3, Informative)

WebMasterP (642061) | more than 2 years ago | (#37875786)

This won't work. Almost all forms of autocross guarantee a driver 3 runs (each driver does one run, then each driver does a second set, etc.). Knowing what time you have to beat after each run is a huge part of autocross. The data has to be input in real time, or at least close so that results can be viewed after each run. This problem gets worse with ProSolo, where there are two courses and challenges require results for a class to figure "handicap times". Additionally, multiple cars are on course at one time (generally like 3), so it's very difficult for one person to do.

In my region, we have some open source custom software that a local member wrote that works pretty good and automatically inputs the times as they come in. I've modified the software to make entering our timing cards faster, but we're a bluetooth bar code reader and some business cars away from having a very streamlined process.

The other thing the author of the original question is missing out is how penalties for hitting cones or missing gates is entered. There has to be some human interaction there. If my region didn't have timing cards, we trusted the computer and the operator completely, we could have 1 person running timing, instead of 2 (I'm not counting the announcer or course control). National level SCCA autocross handles this problem by having someone with a bar code scanner standing near the start line that scans a bar code on your helmet as you drive up.

dont need AI (0)

Anonymous Coward | more than 2 years ago | (#37875292)

put a number on the side of each car, take still photo when car crosses start and finish beams, someone looks at the photos and enters the number next to the time in a spreadsheet. No AI, no problems.

Yes. (0)

Anonymous Coward | more than 2 years ago | (#37875320)

"Do you think it would be possible to design a timing system using off-the-shelf parts and open source solutions to uniquely distinguish about 100 participating vehicles and time them from a start to a finish point, independently of their finishing order?"


Similar cars (2)

LoudMusic (199347) | more than 2 years ago | (#37875326)

What happens if two dudes show up in a blue Miata?

Re:Similar cars (3, Funny)

BoberFett (127537) | more than 2 years ago | (#37875368)

Even worse, what happens when two dudes show up in a Delorean and finish the race before they even start?

Re:Similar cars (1)

Anonymous Coward | more than 2 years ago | (#37875480)

Why would they start the race if they've already finished it?

Re:Similar cars (0)

Anonymous Coward | more than 2 years ago | (#37875718)

How else are they going to get enough run to get up to 88 miles per hour?

Re:Similar cars (0)

Anonymous Coward | more than 2 years ago | (#37875818)

can we turn this into a neutrino joke?

Re:Similar cars (1)

Anonymous Coward | more than 2 years ago | (#37875386)

Then they are probably a nice couple

Re:Similar cars (0)

Anonymous Coward | more than 2 years ago | (#37875434)

What happens if two dudes show up in a blue Miata?

Typically you see two guys in a Miata, usually hairdressers.

Re:Similar cars (0)

Anonymous Coward | more than 2 years ago | (#37875770)

What happens if two dudes show up in a blue Miata?

Would not happen, Miatas are chick cars.

Use AprilTags to identify vehicles (3, Informative)

Anonymous Coward | more than 2 years ago | (#37875380)

They're similar to QR codes but optimized for the needs of robotics (similar to your needs).

In robotics, the main need is for robust recognition, and accuracy.

QR codes are much more complicated because they need a lot more "payload" bytes (millions of unique codes), whereas you only need to distinguish between a couple hundred codes

there is even source code available:

Question asker is retarded (0)

Anonymous Coward | more than 2 years ago | (#37875440)

Seriously? This is beyond stupid. There are plenty of cheap solutions for motorsports timing. Why would anyone compete in your event with your questionably accurate homebrew solution.

Helmats?? Why not numbers? (0)

Anonymous Coward | more than 2 years ago | (#37875456)

Are these drivers going to be required to have helmets making face recondition difficult. I mean know people who have gone autocrossing. It was a convertible so he defiantly used a helmet. Anyway, why not require magnetic numbers on the side of the car. The numbers would be easier to recognize. Even the license plates would be easier to recognize. You could make custom plates with lots of different patterns on them to make super easy. Other Ideas would be IR transmitters.

Not quite that easy... (1)

Anonymous Coward | more than 2 years ago | (#37875472)

I have run timing & scoring for track events (I don't AutoX), but you are under-estimating the problem. Time tolerances for a winning finish can be as close as .0001 seconds. Any variation in the delay for a camera or the time needed to process the image could be a serious problem. Another problem would be car placement, cars will not always cross the line in a nice, neat manner.

Those problems can have real monetary consequences when you factor in the product contingencies (free race tires and other products) that are commonly provided by manufacturers to winning amateur motor sports and AutoX participants. Not to mention the possible impact on season long points races for championships.

Timing loops and lights are very accurate, with loops easily meeting the .0001 second requirement we adhere to. I have personally seen time attack contests decided by a .0003 second margin of victory. Price for loop systems is more than the light based systems, but I have enough experience with the loop systems to know they are very accurate when set up correctly.

If you do want to go home-brew, your best bet might be to mix cameras with timing lights. Get the timing from the lights and let the camera based system assign the the light's times to each specific car assuming you can get the recognition working correctly.

Re:Not quite that easy... (1)

flatulus (260854) | more than 2 years ago | (#37875724)

Timing tolerances of +/- 100 microseconds?

At 100 miles/hr (160 km/hr) that would be a distance of 0.176 inches (4.44mm).

I think you meant "milliseconds" which is 0.001, not 0.0001. Still, multiply the above by ten and you get:

1.76 inches or 44.4 mm

That's a pretty awesome "photo finish."

And for that matter, what about relativistic effects?

Re:Not quite that easy... (1)

geezer nerd (1041858) | more than 2 years ago | (#37876602)

These are interesting numbers, and yes, I verified them with my own calculator.

But it has been stated here that the race is fastest time over a fixed course, not a nose-nose competition between multiple vehicles. That makes the short difference of distance not very relevant.

AForge Rocks (1)

Anonymous Coward | more than 2 years ago | (#37875510)

AForge has the components you need to compliment a IR system: motion tracking and object identification. I've used it on a similar project for a cup team to get corner exit ride heights and yaw. Camera shutter speed shouldn't be much of an issue with just about any off the shelf camera. Camera position will require a bit of testing but that will be pretty obvious. Using video as an alternative with an off the shelf camera is another matter. Here frame rates rule. Even if you jump through the hoops to get 60 FPS you would only have captured the start and stop times with .016 of a second.

outsource everything! (1)

pinfall (2430412) | more than 2 years ago | (#37875512)

Automaticallt take your pics and upload to dropbox, pay mechanical turks to identify and enter data, profit!

Bluetooth? (1)

crow (16139) | more than 2 years ago | (#37875516)

How quickly can Bluetooth establish a connection? Use the optical beams to determine the time that a car passes a point, and give each driver a Bluetooth headset that has been paired with laptops used to record the timing.

You can test the range to make sure it will work--you should only need a few meters. You can get cheap headsets for somewhere around $50, probably less.

I have no idea if this would actually work, but it should be possible to do a test run with parts you probably already have.

Idiots (0)

Anonymous Coward | more than 2 years ago | (#37875554)

Don't re-invent the wheel. Transponders for racing have been around for a long time.
Google for "racing transponder"
I have never seen a problem with timing when I autocross using light interrupters. Perhaps your timing people suck?

Forget autocross, how about foot races? (2)

Radical Moderate (563286) | more than 2 years ago | (#37875572)

As a race organizer, timing chips are a PIA, it would be awesome if facial recognition could track everyone at the start and finish. We're talking up to 10,000 people though, and you'd have to have a photo on file to identify each person. The finish would be easy, everyone is spread out, but at the start you have a lot of faces crossing the starting line simultaneously. Aside from being kind of creepy, is it workable?

Re:Forget autocross, how about foot races? (0)

Anonymous Coward | more than 2 years ago | (#37876012)

No, facial recognition only really work on bad police TV shows.

Facial recognition only sort-of works in perfect laboratory conditions where the lighting can be controlled and duplicated perfectly between the time the photo was originally taken and the time the photo is compared. It currently has no real use in real life (except in scamming the US government into buying expensive useless facial recognition systems).

pushbroom camera (0)

Anonymous Coward | more than 2 years ago | (#37875600)

Since the cars are moving, I'd think a pushbroom camera setup (maybe using the CCD from a document scanner -- not sure if they can be read out fast enough, need 1kHz or faster) would work better than repeated 2D exposures -- less redundant information means you can sample faster, so instead of trying to interpolate between images for exact timing (essentially reconstituting time from distance), you get everything as time directly, and the resolution you get is the resolution you get. You can still recognize cars (read the numbers or whatever) from the continuous strip, but timing is as "easy" (easy for a human, hard for a computer) as picking the first column the car appears in. If you need millisecond-accurate timing, you may well have to let the computer get a best guess, and then manually refine it.

GPS? (1)

flatulus (260854) | more than 2 years ago | (#37875660)

I know this has a scalability problem (i.e. the cost of equipment goes up linearly with the number of contestants) but you could build a self-contained GPS device that tracks a car's position throughout the event. Have it record position information to flash as often as possible (Sparkfun has a GPS receiver that will update position 10 times/sec for US $61). At the end of the event, everyone turns in their GPS device and their position recordings are uploaded into a computer.

Now one may argue that GPS position error could be enough to make the winner ambiguous (i.e. "photo finish"). But position errors due to RF propagation are "systemic", in that they would affect all receivers in the same vicinity pretty much equally. Further, with a large number of position samples and high update rate, post-processing could be done to calculate trajectory of the possible winners as they approach the finish line. It simply isn't possible to accelerate or decelerate so quickly that you can't interpolate position and velocity in the vicinity of the finish line.

For the "systemic position errors", a single reference GPS receiver at a stationary location next to the finish line can be used to determine position "wander" due to RF, ephemeris, selective availability (even though it's off these days) and use this to subtract out this systemic error from everyones' position data.

Would be fun to build :-)

Re:GPS? (1)

Antisyzygy (1495469) | more than 2 years ago | (#37876312)

http://ask.slashdot.org/comments.pl?sid=2499210&cid=37875118 [slashdot.org] There are image processing techniques that would work with relatively small identification marks and a sufficiently "good enough" camera. The processing may take 5 minutes but you can cut to commercial and have a human verify it later. The issue is getting the original system accurate enough you are 99 percent sure whoever crossed the line first, crossed it. Facial recognition systems already have this level of accuracy. Just like voting systems however, for fairness you need human review before passing definite judgement. Apply some science and you would have a killer product there. Im surprised there aren't more industries employing at least one academic to make their systems more cutting edge.

RFID (1)

Anonymous Coward | more than 2 years ago | (#37875688)

Don't know if it would work in auto sports but sounds like a use for RFID, http://en.wikipedia.org/wiki/Radio-frequency_identification#Race_timing

Practical experience with autox T&S systems (3, Informative)

cojsl (694820) | more than 2 years ago | (#37875714)

I'm an autocrosser with experience setting up, maintaining, and troubleshooting both an older T&S system, and the new system used by the SCCA at national events. Ours was the first local region to install the new "national" system, so I'm familiar with the "issues" surrounding the current T&S options.

There are several practical issues with optical systems for automated vehicle recognition- number and class markings are already tough to get consistent without requiring an additional barcode or QR large enough (some competitors would gripe about a huge barcode) to be useful at the 30'+ distance finish line sensors are set back to minimize getting hit by spinning cars. Add in the fact that existing markings some times fall off on course, or competitors in dual driver cars forget to change numbers between runs, and it's tough to be certain you'd have something consistent to try to recognize.

The national T&S system uses a wireless barcode reader operated by a worker in the starting queue to read stickers placed on competitors helmets to register cars in the T&S software. Locally, we position the T&S trailer to allow the operators to manually enter vehicles as they enter the start queue. Human eyes really are the most flexible here "shouldn't 80ES be 180ES?".

I like one of the comments above about a webcam triggered by the finish light taking a picture with a clock display in it. Unless there was OCR to immediately post the result to the software, the results feedback would be too slow for our region- we have real time announcement of finish stats, and the software can post results to a web server real time for smartphone access in paddock. The T&S software uploads a small file to the web server in the 20ish second gap between finishing cars.

Apologies for not offering solutions, but hopefully the extra info about some of the issues can help shape a solution.

Re:Practical experience with autox T&S systems (1)

JoeMerchant (803320) | more than 2 years ago | (#37876388)

The national T&S system uses a wireless barcode reader operated by a worker in the starting queue to read stickers placed on competitors helmets to register cars in the T&S software.

At my local events, there are usually a few people sharing loaner helmets...

Use the open source Predator Tracking (2)

wmaiouiru (1420135) | more than 2 years ago | (#37875784)

This is pretty much a tracking problem, I would use the open source Predator Tracking algorithm to track each of the car simultaneously. The problem I see is if it is going to be fast enough for 100 cars, but it is worth to investigate it. http://info.ee.surrey.ac.uk/Personal/Z.Kalal/ [surrey.ac.uk] Alternatively, thinking about using open source-hardware as a solution, use the open source Arduino Micro-controller Piece the sensor you need, and you will have your system at a much lower price ! http://www.arduino.cc/ [arduino.cc]

Re:Use the open source Predator Tracking (1)

JoeMerchant (803320) | more than 2 years ago | (#37876398)

Don't know if Predator refers to the military UAV, but it got me thinking, float a camera on a balloon and video the whole track from above....

RFID? (2)

ssyladin (458003) | more than 2 years ago | (#37875792)

Why not put an RFID tracker on each car? They're relatively cheap and you can store some encrypted identifier in it. Pillar or mat sensors would pick up when the car crosses the line, though it might be a challenge finding sensors that'd pick up a car at 60mph...

Re:RFID? (0)

Anonymous Coward | more than 2 years ago | (#37876382)

RFID mat idea doesn't work. Been there and tried it when the blokart (Land yacht) club was wanting a start system. Then AMB came out with the ChipX system which works great. All we did was make our own 50m wide antenna, and customised a cheap timing program to work with it.

Another club used AMB's previous system which was designed for cars and had active tags. Their solution of a 9V battery and a switch had issues - oops kicked switch off / forgot to turn on or off / battery's going flat / I won as I just put a new battery in etc... which was why we tried the passive RFID idea. Speed isn't an issue if you use HF chips.

Why mat doesn't work: Ground plane effect. Found instructions on TI's website to make a antenna about 0.6x x 1.2m. We were going to have 8 in a row. We could read a tag about 1m away from it when holding the antenna vertical, putting it on the ground dropped it to ~500mm, and then we made the mistake of getting a thick rubber mat to protect it (Rubber has a poor permeability) So distance was down to about 250mm high off the top of the mat which had turned into a hump due to putting a couple of layers of foam under the antenna's to reduce the ground effect. And then it worked fine indoors / evening but not during the day. Figured out the tags had exposed IC's and the UV in the sunlight (UV quite strong in New Zealand - clear air / ozone hole etc) and must have been corrupting its operation. Painted the tags black to solve it. Also mats were slow and hard to deploy in the wind so overall wasn't a great solution in practise.. So its why the car RFID systems are mounted above or beside the gate to get a tag on the dash.

There are companies that offer RFID systems for running etc - but footsteps on a mat is a lot easier proposition than wheels running over a lump (The mat would get pushed around as karts went over it) - or they have figured out how to get around the ground plane effect.

Selective Wavelength Emission/Absorption (2)

cosm (1072588) | more than 2 years ago | (#37875836)

Special paint that reflects/absorbs only at certain frequencies. You have a 'stickers' that go on all four corners of the vehicle. The finish line has a spread-spectrum laser array blasting across it. When a car crosses the line, each car is tagged with unique tape. The laser light reflected will be unique to the vehicle. You triangulate the reflected lights timings and use that in conjunction with the wavelength reflected back and you've got a car and you've got a time.

Unique tape on each car. Cheap, replaceable. Not a perfect solution, but some variant of this involving selected emission/absorption is a winning ticket. I made this up in 1 minute and have no idea if there are any preexisting solutions that do this. For the pedants; yes tape could peel off and yes people could cheat some how I'm sure, blah blah blah, and I'm sure there is a more optimal solution blah blah blah, and I'm sure you'll have issues in X Y Z situation with A B C conditions blah blah blah. Go make something better and sell it.

Like a SPECS camera? (0)

Anonymous Coward | more than 2 years ago | (#37875910)

Sounds like you want something that works like the average speed check cameras we have in the UK: http://en.wikipedia.org/wiki/SPECS_%28speed_camera

Autocross or footraces, just use existing tech (1)

rust627 (1072296) | more than 2 years ago | (#37875916)

An Australian security company has developed and is selling to petrol stations and some other businesses a number plate recognition program that is capable (I have seen it in operation) of reading and identifying car number plates with reasonable (98% +) accuracy at a distance of about 50 Metres (Maybe more, but the one I saw was working at that distance) on cars driving on a normal suburban road (speed limit 60 Kmh).
With larger numbers such as the display numbers on a race car, or the vest on a foot racer I don't think it would have any difficulty. And for the racers who 'forget' to change their numbers across multiple vehicles, well I am sure that they could live with their personal results being posted a little later after someone had checked the image generated as they crossed the line.
In some events at the club level in rallying you are disqualified if you are not showing your numbers for the various judges and officials to easily identify you during the race (much as that goes against the general slashdot desire for privacy and anonymity at all times)

Yep - if you can do the lifting (1)

Mr. Underbridge (666784) | more than 2 years ago | (#37875952)

There has been a lot of work for recognizing images in video. Here, if you're smart you should be able to do the recognition given a single still, which means it's just ordinary image processing after extraction from the video.

Make it easier on yourself by making the numbers something like bright yellow on blue with a white border (for instance). Then just look for segments of each image with high response for yellow and blue. Then extract the video and pass it through an OCR tool.

Also, put the camera somewhere like the apex of a turn where they have to slow down and you'll be perpendicular to the side of the car (with enough distance that your camera rig doesn't get creamed).

helmet! (0)

Anonymous Coward | more than 2 years ago | (#37875956)

Guess no one ever wears a full face helmet with a mirrored visor where he plays. Would be much easier to id the car number on the side of the vehicle.

Great idea but addressing issue of latency? (2)

w0mprat (1317953) | more than 2 years ago | (#37875966)

Accuracy hard to achieve. You'd have to carefully track the latency between the webcams image and the software timestamping the video data. Not an easy coding excercise, and would require calibration with accurate timing equipment. This latency also better be stable. I don't know too much about using linux for realtime work but I have heard it has some latency issues at the kernel level that causes trouble for audio pro's.

If you want to do this with a web cam and a bit of code on a linux machine, well 30fps video gets you a lower bound of 33ms time resolution. That's before the camera feeds to the USB data channel, then any gamer will tell you USB has some latency, and then software has to process the image data. High powered laptop and a good camera might be able to do all this as low as 100ms before it can timestamp the data. Image processing for identifying the vehicle can then happen at any time. This would need to be carefully accounted for in deciding who wins a race.

Proper race timing needs to be 3 decimal places, at 200kph (124mph) a 1/1000th of a second ammounts to 6cm of difference. Races are really won and lost on as little as this and often the timing is done even finer.

Am I missing something? (1)

cob666 (656740) | more than 2 years ago | (#37876022)

First, I'm not familiar with car racing so apologies if my observation is idiotic.

The problem I see with having bar codes or RFID measure the time is how the car crosses the finish line. Because the OP mentioned a beam being interrupted I imagine the finish is determined by the front of the car touching the finish line (not unlike any other type of racing) so if the time is measured by a barcode or image on the roof or door then how do you match that with the front of the vehicle. Also, if the time is measured by when a sensor picks up an RFID tag then again you have issues with mat / receiver sensitivity and tolerances in the transponder triggering the sensor.

Because only one car is on the track at a time you do have some wiggle room, I'm sure there would be many ways to accomplish this but it seems like you're already doing what would seem like the 'best' approach:
System where both IR beams are hooked up the same time, beam 1 starts the time, beam 2 stops the timer. Before each car, race official 'initialized' the timer system by entering information about the car racing, this would solve two issues, the first is that it would reset the timer back to zero, the other being that if the previous car didn't cross the finish beam to stop the timer, the initialize process would automagically flag the previous car as not finishing (not sure how that would effect the time for that driver though). You could also put in other beams throughout the course that would give you times up to that point in the race. So, if you have a start beam, mid course beam and finish line beam, the start beam would start the time, the mid course beam would just grab the time but keep the timer going, the finish line beam would stop the timer.

Is this feasible, too simplistic or am I overlooking something important?

two cameras? (1)

ai4px (1244212) | more than 2 years ago | (#37876056)

Two cameras? One camera that the cars drive over or under and a 2nd camera perpendicular looking at the side of the same car. Place a barcode on the front of the car... shutter speed would not be so much of an issue as the car would approach the camera for a relatively long period of time. The second camera marks when the car crosses the finish line.

arch (0)

Anonymous Coward | more than 2 years ago | (#37876070)

Put large visible marker such as a number on roof or hood of cars. Build arch above finish line. Put cameras on arch facing towards the ground. Film cars going through the finish line. Win fabulous prizes.

Do not complicate the problem (1)

Anonymous Coward | more than 2 years ago | (#37876072)

I say have you heard of the Boston marathon or near any popular marathon. They attach a RFID chip to the sneaker and record when it crosses the start and at the end. They collect the start and stop of thousands of people on the same day and crossing in large groups out of order.

There is also open source license plate recognition.
You could have every driver use a fingerprint reader and part of the start and finish is the drivers running to/from the car.

Similar, for RC (2)

Spiked_Three (626260) | more than 2 years ago | (#37876082)

I have been working on a racing timing system for RC; https://picasaweb.google.com/104667803940601062545/Spiked3#5624165831383052962 [google.com] is an older screenshot, but you get the idea. In my research I came across this; https://sites.google.com/site/easylapcounter/home [google.com] which does recognize based on imagery. Your idea certainly seems feasible. for RC, we just byte the bullet and use the expensive MyLaps (AMB) transponder system ($3000 base + $125 per transponder). I assume they have some huge patent on it because it seems like it would easy and cheap to copy, yet no one has done it. Good luck.

Re:Similar, for RC (0)

Anonymous Coward | more than 2 years ago | (#37876708)

There is another transponder manufacturer, but I don't think they do RC:


Magnetic stickers, eh? (1)

jafo (11982) | more than 2 years ago | (#37876198)

The problem with magnetic stickers is... Corvettes have fiberglass body panels. :-)

I once ran timing, here are my thoughts:

Personally, I don't think that transponders are expensive, and I think they'd be a great solution which would absolutely fail because of politics. "You mean I have to buy a $100 device (or rent for $5/event) to mount to my $40,000 car that has $2,000 rims and $1,400 tires?!? What do you think I am, made of money?!?"

I suspect you won't be able to do good detection except if the cars stop at the end. That's something you'll have to play with though, maybe you can set up a zone past the end where they have to stop to get recognized, or *MAYBE* the camera can deal with them if they stick to the recommended speed off the track. Cameras are very bad at getting sharp shots of sideways motion though. It'll also depend on the conditions out.

I imagine you will need to use a hardware timing device that runs in real-time and then you can pull the time off in the non-realtime OS. That or you'll need to run real-time OS extensions. Maybe you can get something reasonable out of a hardware interrupt like a serial/parallel port line change. The normal x86 Linux clock is 1ms resolution, and plenty of jitter, so just expecting to use the clock under Linux is probably unrealistic.

These people are as serious as a heart attack about this hobby. Saying "Accurate to within a few thou is probably good enough" is a good way to see exactly how good your insurance plan is. :-)

You're going to have to deal with things like a car leaving the starting line with "185" on it's side and crossing the finish with "85", "18", or even "1 5" on it. :-)

The "Predator" OpenCV system sounds like it would be awesome to try in this situation.

Consider setting up a place where the cars can go to get recognized and their number entered, maybe at the starting line, but maybe a dedicated area. Predator/OpenCV may be able to detect things like the letter that fell off during the run, but it may also mis-detect in some cases. You'll probably need someone eye-balling the start and finish anyway.

Good luck with that. I tried writing up some documentation for how to run the system I at our Autocross after they trained me on it, and I had my ass handed to me...

Get the right camera (1)

RightwingNutjob (1302813) | more than 2 years ago | (#37876210)

QR codes are the right idea. The real money you'll need to spend is on the camera and near-realtime PC to process it.

I've had good luck using GigEVision under Linux. There's a bunch of vendors out there that have Linux drivers for their GigEVision cameras and the specialized acquisition hardware is just an ethernet card. You probably want something that goes at least 30 fps sustained (probably about 1-3k for a camera, depending on resolution and bells and whistles). That's plenty enough to be able to interpolate vehicle trajectories between frames to get down to millimeter accuracy, assuming your optics package gives you the resolution.

Webcams are probably a no-go because you'll want higher resolution in order to be able to observe and recognize the codes over a wide finishline area, and USB 2.0 is limited in the amount of bandwidth you can get.

Just read the numbers (1)

oaksey (585738) | more than 2 years ago | (#37876462)

I've heard about systems in cities that read number plates and time you between their different locations to see if you are speeding, I'm guessing a system like this could be used, just a matter of if it is cost effective or not.

Backup (1)

SEWilco (27983) | more than 2 years ago | (#37876478)

The crucial data is the timing, while identification is a task. You must record the timing, but it is not crucial to perform the identification in real time, is it? You just need to be able to eventually produce the timed list. Record the timing and photo information in a way which lets you later review and compare both, so if you miss an identification it can be done later.

Yes, try to do the identification task immediately, but ensure that the system has the needed abilities to deal with problems. Rain, mud, or a bug on your lens could interfere with the intended operation.

Magnets? Maybe not (1)

SEWilco (27983) | more than 2 years ago | (#37876488)

Identify unique shape, numbers, barcode, qr code or similar in the images, that have been attached using a magnet to the vehicle's door.

Not all vehicles are steel. Magnets might not hold your barcode on all vehicles.

External ID Laser? (0)

Anonymous Coward | more than 2 years ago | (#37876528)

What about putting a simple laser system on the side of the car which, like an IR remote but with increased focus, emits an identifiable code. The finish line could have a detector for this.
The point behind suggesting laser is

A) less likely to be disrupted by differing light conditions which would affect IR
B) less likely to be disrupted by differing heat condition which would again affect IR
C) By placing them and exact distance from the front of each car you can be sure of accurate measurement.

Should be possible with an off the shelf laser pointer for the emitter, coupled with an arduino or similar to get the signalling.
Detector would need to be an array of optic sensors in the wavelength range of the emitter, and again probably simply an arduino to decode the signal, and send the details to a controlling PC/Laptop

http://www.robotroom.com/Laser-Detector-Remote-Control.html could be a starting point for the reciever system.

Why not use RFID tags? (1)

blanchae (965013) | more than 2 years ago | (#37876584)

Seems that RFID tags on the cars would solve that. No need to use facial recognition software - too complicated. In the railway industry they use barcodes on the side of railcars to keep track of them. That's another inexpensive idea. Just have the cars go single file through a laser barcode reader or through the local supermarket checkout...

Very Easy (0)

Anonymous Coward | more than 2 years ago | (#37876614)

Disclaimer: I am a roboticist studying computer vison. This is very easy. Get one overhead camera over the finish line. Put a QR code on every vehicle (or even better, a scale invariant marker, or even just a solid color if you have few enough vehicles). Crank down the exposure time on the camera until it can just barely see the codes as a car passes underneath it at speed. This might require you to purchase a somewhat higher speed camera. If you can't do that, consider pointing the camera away from the finish line so that the camera has more time to see the cars coming. Find the transform from the camera to the finish line. The line forms a plane in space pointing orthogonal to the ground. The camera then detects every car just before it crosses the finish line. Project each QR code into the camera frame with OpenCV. When they cross the finish plane, they've won. Simply count off the QR codes as they cross the plane.

90% TSA Employees have less than 6 grade education (0)

Anonymous Coward | more than 2 years ago | (#37876642)

TSA employees need help.

They need a great amount of help.

On a day to day basis, 90% of TSA employees can't recognize the difference in Caucasian and Negro.

It may be that 90% of TSA employees are ... mixed race.

The may also explain why TSA employees can't distinguish between a gun and candy, that in a carry-on bag.

Oh dear.

kiss (0)

Anonymous Coward | more than 2 years ago | (#37876720)

do you have to id the driver/car and get the timing at the same moment? In athletic races over distance eg marathons etc finishing competitors are timed over the line then enter a 'funnel' where they sort themselves into order and are id'd . it works even for very large numbers of competitors. so for your races you barcode each driver, id him at the start. time him at the finish then id when he stops. can be done with a pair of handheld scanners. if your competitors aint gentlemen set up a photo finish camera to resolve disputes.

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account