Photo Finish options

General timing system discussions.
PineNut
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Photo Finish options

Post by PineNut » Fri Jan 11, 2008 11:26 pm

Has anyone been seccessful in having a video or camera replay system at the finish line?

I have been toying with our old Canon Power shot camera. If I hook it into a tv and keep the image up for 10 secs, I can take a picture, and it will display the finish for 10 secs. Then gets ready for the next picture. I can always go back and look at the old races since they would all be saved. I have a laser gate from Microwizards that is not being used and can use that to trigger the camera.

Any thoughts? There are cheaper web cams out there too (~$5 - $10). Have a seperate PC run the web cam, and have the display manager run this to a large tv for the audience.

Any help would be appreciated.



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Re: Photo Finish options

Post by Stan Pope » Sat Jan 12, 2008 2:15 am

PineNut wrote:Any thoughts? There are cheaper web cams out there too (~$5 - $10). Have a seperate PC run the web cam, and have the display manager run this to a large tv for the audience.
Are you doing this with the GPRM software? I think Randy put some finish line video capability in during the last year or so.

At least some of the web cam's that I've seen don't have a fast enough scan rate to allow you to call a race using one.

A real techie might be able to rework a web cam and its driver to function the way the photo-finish mechanisms at the horse tracks works ... the X-axis runs across the finish line and the Y-axis is time! Even a rather cheap web cam would be fast enough to do that, I think. The picture could be as many seconds long as the race requires, although starting with the gate opening and stopping when the last car crossed would be plenty. And the pic could even be processed by program to call the winner! Hmmm...

If you have ever looked at the photo from a photo-finish camera, you probably agree that the pictures are rather eerie, though. A fast car looks short, and a slow car looks long. Any side-to-side movement of the car would make the car look jagged!


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Re: Photo Finish options

Post by gpraceman » Sat Jan 12, 2008 2:38 pm

eTekGadget, makers of the SmartLine timer do offer a photo finish device and software. It does depend on their timer to provide the signal on when to take the photo.

If you are not using the SmartLine timer and photo finish device, then you would need some way to trigger the camera to take the picture at the right moment. The SmartLine timer will trigger the photo finish device once the first car has crossed the finish. You could setup your laser sensor at the finish but then you need to figure out how to get that to trip the camera to take the photo. You would also have to figure out how to power the laser (since it normally is controlled from the Fast Track timer).

Anyways, with a photo finish I do see potential issues where a car could pass up another car right at the finish (say to take 2nd place), but looking at a photo taken when the first car crosses, that car may look to be in 3rd place. So, if 2nd place is being contested, the photo may not tell the true story. Most of the time that wouldn't be an issue, but the potential is there for that scenario.

What Stan is referring to, in regards to GrandPrix Race Manager, is the interface that it has with the RaceReplay software. RaceReplay will record video and do an instant replay of the heat. If you use it along with GPRM, GPRM can tell RR when to start recording, when to stop recording and when to do the replay.

With RaceReplay or video player software, you can step through the video frames, one at a time, of a tight race and use it to help determine the finish of a contested race. A disclaimer though. If you are not using a DV camera, you will have a more noticeable interlaced image effect (looks fuzzy, not crisp), due to the nature of interlaced video. DV cameras provide better resolution and up to double the frame rate as a regular video camera.

You can use a webcam for a photo finish (assuming you had a means to trigger it at the right moment) or even to capture video with, but the resolution of most of those is pretty mediocre (you get what you pay for).


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Re: Photo Finish options

Post by Stan Pope » Sat Jan 12, 2008 3:19 pm

gpraceman wrote: Anyways, with a photo finish I do see potential issues where a car could pass up another car right at the finish (say to take 2nd place), but looking at a photo taken when the first car crosses, that car may look to be in 3rd place. Most of the time that wouldn't be an issue, but the potential is there.
This would not be an issue with the "techie solution" that I outlined. But, I don't know if the hardware and /or software that would be required is available or reasonable to "make from."

That solution only looks at the finish line (one row of pixels) and stores that row of pixels every 1/N seconds showing what is at that point at each time interval. Since only one row is scanned, rather than an entire matrix, it can take many more images per second and give exceptional resolution and economically span a period of several seconds. It would show the first car crossing and, then, a few lines down the picture, it would show the second car crossing, etc.

There is a common analogy in everyday use: a flat bed scanner. The difference is that in a scanner, the "camera" moves and in the proposed method, the page to be scanned moves and changes as it moves.)


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Re: Photo Finish options

Post by PineNut » Sun Jan 13, 2008 9:32 am

Stan,

Thanks for the reply. Here is what I was thinking: we purchased a microwizards timer. It came with a laser start gate and a microswitch. I had a difficult time keeping the laser lined up (we also purchased a 4 lane alum Piantodosi track). We just put the micro switch that also came with the timer and it works like a charm - maybe a little more low tech, but more robust. As every time you reset the gate, it moves the laser ever so slightly and it trips the gate by default.

So - I was thinking of using the laser gate, position it somewhere down the track ahead of the finish. Given the delay of a point and shoot or a webcam, you could adjust where the gate is to have it snap the picture at the right time. As Randy mentioned, if it doesn't fire at the right time, then you could miss the race of 2nd place could be coming across sooner (I don't think the web cams are fast enough for continous shooting unless you stream video (cheap ones are 30 frames per sec and cost $10). More expensive ones are $60 at Sams Club and do 90 fps. The more expensive ones also have a snap shot feature built in with 2 MB res. More than enough to call a race.

If you are wondering why do we want a photo finish when we already have a fast track timer - well, we got it brand new last year (we had micro wzards in the past). We ran our pack race - no complaints. By the way- we use Raceview software. We had it for a few years. So on to the district race at the mall. The finish was set under a sky light. After 60 vars raced for the Lions and I am handing out trophies, a woman is screaming "Excuse me SIR!". After I hand the trophies out, she then complains that "Lane 3 did not record her sons race correctly!" I explain to her about the lane sensors, the fact that she might be watching her own sons car, etc. etc. etc.

Sure enough, later on, Lane 3 did have some issues. The sensor was getting too much light. I have since blocked the holes with electrical tape and now they are ultra senstive (a paper clip will trip the lane). During the race though, I had 2 judges at the bottom of the track giving me a thumbs up on the finish order or the track LED - before I would accept the results.

But my thought is if we had a photo finish, we could verify the electronics not to mention the excitement factor.

Randy - do you offer a demo version of your software? What advantage would be gain over the Raceview, as I do like the graphics of Raceview as well - with the display of 1, 2, 3, 4 etc.

Thanks

Steve



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Re: Photo Finish options

Post by gpraceman » Sun Jan 13, 2008 9:46 am

PineNut wrote:Randy - do you offer a demo version of your software? What advantage would be gain over the Raceview, as I do like the graphics of Raceview as well - with the display of 1, 2, 3, 4 etc.
We do have downloads available for GrandPrix Race Manager and RaceReplay. They will act as demos until a valid serial number is entered.

GrandPrix Race Manager - http://grandprix-software-central.com/gprm/
RaceReplay - http://www.grandprix-software-central.com/racereplay/

Then look for the "Download the Software" link.

I do wonder if eTekGadget would be interested in working with you on creating a sensor trip for their photo finish setup (as opposed to triggering from their timer). It wouldn't hurt to ask. It would definitely be easier to take something off the shelf and try to adapt it, if you really want the photo finish ability.


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Re: Photo Finish options

Post by Stan Pope » Sun Jan 13, 2008 11:38 am

PineNut wrote:If you are wondering why do we want a photo finish when we already have a fast track timer - well, we got it brand new last year (we had micro wzards in the past). We ran our pack race - no complaints. By the way- we use Raceview software. We had it for a few years. So on to the district race at the mall. The finish was set under a sky light. After 60 vars raced for the Lions and I am handing out trophies, a woman is screaming "Excuse me SIR!". After I hand the trophies out, she then complains that "Lane 3 did not record her sons race correctly!" I explain to her about the lane sensors, the fact that she might be watching her own sons car, etc. etc. etc.

Sure enough, later on, Lane 3 did have some issues. The sensor was getting too much light. I have since blocked the holes with electrical tape and now they are ultra senstive (a paper clip will trip the lane). During the race though, I had 2 judges at the bottom of the track giving me a thumbs up on the finish order or the track LED - before I would accept the results.

But my thought is if we had a photo finish, we could verify the electronics not to mention the excitement factor.
Well, no, I wasn't wondering. You are far from the first to be victim of that trap!

You know now that your audience should not be responsible for telling you if the equipment is working. Often they will tell you if it is not working correctly. But you need a less biased judges on station so that problems are reliably detected at the time of failure ... that is the time that you can actually do something about them. After you have given out the trophies is a really bad time to find out that it didn't work! The judges need to be "on duty" even when things appear to be going right! Will you ever run a competition without them again?

But judges can't tell if times are sensed and recorded correctly. At best they can tell you if the car was detected at approximately the time it passed the finish line. "Approximate" isn't good enough when trophies are won or lost by 0.001 seconds!

And even the faster camera's 90 frames per second is not sufficient to prove times. That is more than 0.01 seconds between pictures. It will probably tell you if finish order is recorded correctly.

But, lets look at the cheap camera's line scan rate. If the picture taken by a web cam consisted of 300 lines, then the 30 fps camera is capable of 30 times 300 lines per second ... 9,000 lines per sec or about 0.0001 seconds per line. Even the technology in a cheap camera are sufficient if they had the right mission: recording the "contents" of the finish line every 0.0005 seconds and storing that "time state" as a line in a "time photo".

My suggestion (earlier in this thread) for true photo-finish is incredibly strong ... It can run for the duration of each heat and only require storage comparable to one photo. Since most of the time the "picture" (actually the row of pixels showing the finish line) is identical (because no cars are present), the "image" is capable of extreme compression with no loss of data.

Then, with a bit of electronics and software, time marks can be added to the image showing the time represented by various rows of pixels in the image. So, you have the ability in one photo to validate both finish order and individual heat times!

The cost? That ought to be about the same as a flatbed scanner or modest web cam!


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Re: Photo Finish options

Post by Stan Pope » Sun Jan 13, 2008 3:55 pm

Finally decided to visit my friend Google to see what was already out there. This afternoon, I found these sites.

Wikipedia gives some useful background which is largely consistent with what I wrote above. See http://en.wikipedia.org/wiki/Photo_finish.

There is also a nice article that includes info on interpretation of photo finish pictures at http://www.rit.edu/~andpph/text-photofinish-race.html. It uses Polaroid photos and crude technology, but the interprtation info is good.

eTekGadget.com sells a Video Capture Device which it calls "a photo finish picture", but which does not conform to the true photo finish concept described in Wikipedia. See
http://www.etekgadget.com/photofinish.htm.

TimeTronics has implemented the hardware and software and says that it is currently in use in a variety of racing venues. It appears to fully cover the features that a PWD race environment would need. Bet the $ are bigger, though ... way bigger! :( See http://www.timetronics.be/products/macfinish.php. One of their offerings includes this description: "The MF II SCSI is a professional colour photo-finish system, which electronically records the finish line up to 2000 times per second (with a resolution of 0.0005 of a second)." So, my earlier estimate was "in the ball park!"


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Re: Photo Finish options

Post by gpraceman » Sun Jan 13, 2008 7:35 pm

Stan Pope wrote:Bet the $ are bigger, though ... way bigger!
Yeah, I bet it would be very expensive.

Anyways, what is the real goal to having a photo finish? Is it to determine results of a contested race? I'd rather have a dependable timer for that and as Stan pointed out, it wouldn't necessarily yield accurate results. Or is it for the cool factor? If so, a more budget minded solution will do just fine.


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Re: Photo Finish options

Post by Stan Pope » Sun Jan 13, 2008 7:51 pm

I actually think that the true photo finish (not the eTek wannabe) would be more accurate than most timing equipment and more reliable for some of the car variations. And, its results are preservable and reviewable. Imagine giving the heat winners the pics of their victories! :)

Guess it is time to take a cheap web cam apart and see what makes it tick! :) Also I ought to look at any engineering details that I can scratch up on the web!


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Re: Photo Finish options

Post by gpraceman » Sun Jan 13, 2008 7:55 pm

Stan Pope wrote:I actually think that the true photo finish (not the eTek wannabe) would be more accurate than most timing equipment and more reliable for some of the car variations. And, its results are preservable and reviewable. Imagine giving the heat winners the pics of their victories! :)

Guess it is time to take a cheap web cam apart and see what makes it tick! :) Also I ought to look at any engineering details that I can scratch up on the web!
Maybe you found yourself a new niche in this market :wink: Good luck to you.


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Re: Photo Finish options

Post by Stan Pope » Sun Jan 13, 2008 9:36 pm

Yeah, maybe there is a niche ... what irritates me is that the "picture taking" technology of my little digital camera is an order of magnitude more complex than that required in a photo-finish camera!

Where the technical difficulty is encountered is getting the camera aligned to the finish line, keeping it aligned there and streaming an 800X20,000 "image" (10 seconds at max resolution) out to the computer!

But ... there is a billion buyer sized market for a digital camera, and the market for a photo finish camera is maybe 10,000? Annual sales 100,000,000 vs. 1,000. That allows a lot of technology to be integrated into my little digital camera and drive the per unit development cost way down. Considering some of the stuff that is in these cameras (both photo and video) I bet one of 'em is lying around out there with a mode setting that does exactly what we want.


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Re: Photo Finish options

Post by pack529holycross » Mon Jan 14, 2008 5:43 am

perhaps we can approach this not from a perspective of consumers trying to adapt consumer-available gear to a speciaized use, and think about what it would take to research what professional sports videography professionals use in modern sports events. I would start with large pro-sumer clearinghouse companies like Broadway Photo or B&H. Ill look up a few things when I get back from my appointments this afternoon.


Nicholas



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Re: Photo Finish options

Post by PineNut » Mon Jan 14, 2008 1:52 pm

Stan,

At first I wasn't understanding your comparisons, but after thinking about it, I think I got it (time vs x-axis). And then trying to replicate that with a webcam = too complicated for a part time pine nut.

I am thinking of either one still image or maybe 3-4 (as fast as the camera can fire) or a video camera.

The still image has issues as pointed out by Randy but that's what the electronics are for after all, right?

We did institute judges at the finish line, but even then, after 20 or so races got lazy and defaulted to the LED display (easy to do).

I just hope that there is not such a thing as the line being too sensitive - ie false trips.

Its time to get some hardware and start playing around. I do know that Logitech sells a webcam (30 fps) that would be great for mounting on top of the finish line - looking down, and has built in software to record and replay video clip. You could trigger manually - start before you trigger the gate, then stop once they all went through and replay it. The cheapest logitech that comes with the software is the Pro 9000 camera (software called RightLight). Its $70-90 depending on where you can find it.



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Re: Photo Finish options

Post by doct1010 » Mon Jan 14, 2008 2:32 pm

Stan Pope wrote: I bet one of 'em is lying around out there with a mode setting that does exactly what we want.
Considering cell phones can take pictures and stream 10-15 sec of video I'm sure you are right!



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