Show HN: We put an iPhone on the front wheel of a car

http://blog.evilwindowdog.com/post/88969373226/extreme-car-experiment-horizon

by stelabouras • 12 years ago

380 107 12 years ago

blog.evilwindowdog.com

binarymax• 12 years ago

I have some serious sea legs and almost never get motion sickness. The fullscreen youtube vid got me. Great experiment.

matt_morgan• 12 years ago

I'm getting motion sickness just thinking about it. Haven't even watched yet.

kp25• 12 years ago

Do watch it, Great Experiment. Got Sick..

endijs• 12 years ago

Why on Earth you had to tell that? After reading your comment I had to go and check out video on my own... Will not do that anymore.

larrys4• 12 years ago

Same happened and I didn't even watch full screen.

Maybe this is a way to test those sea bands that I have that I think generally work. But now I do have motion sickness and felt it almost right away.

NAFV_P3• 12 years ago

The video did make me feel quite queasy, but it is not as bad as Descent [0].

[0] http://en.wikipedia.org/wiki/Descent_(video_game)

ddt• 12 years ago

Oh man, so many memories of giving motion sickness to my friends and parents watching me play Descent.

NaOH• 12 years ago

I've never been a gamer. Except for Descent. And Descent II. I still have them and every few years play them on an old Mac. The queasiness kicks in every time I start playing them again.

msutherl• 12 years ago

Not having heard of Descent, I was really hoping it was a game that consisted entirely of falling.

aaronsnoswell• 12 years ago

Grew up playing this game - thanks for reminding me of it :)

pronoiac• 12 years ago

It looks like they don't account for the rolling shutter on the camera.

thisjepisje• 12 years ago

Drive faster god darnit!

lewisflude• 12 years ago

A really cool way of showing off Horizon. Good work guys!

ekosnow• 12 years ago

oooohh!!! great experiment with great results!!

bra1n• 12 years ago

Better title: "Show HN: We put an iPhone on the front wheel of a car and drove really slowly for less than 10 seconds at a time"

Raphmedia• 12 years ago

50 km/h is fast enough for this experiment if you ask me.

sukuriant• 12 years ago

614 revolutions per minute on the tire, assuming a 17" wheel, is still pretty impressive.

universome• 12 years ago

Cool experiment, I just dont get, how that idea came to your mind? - "Oh, man, look, I have an iPhone. Guess what?" - "Yeah, we should certainly put it on a wheel of a car!"

cgh• 12 years ago

Starting from the second sentence in the article:

"We all know by now that Horizon shoots perfect horizontal videos, even if you rotate your device while shooting! We wanted to stress Horizon’s capabilities by using it under extreme circumstances."

fredsted• 12 years ago

It's so obvious which people commented without reading the article in this thread.

stelabouras2• 12 years ago

Thank you for the support! Here are 5 promo codes so you can try our app for free! http://codehookup.com/2291e14c

rohith_14_04• 12 years ago

Missed it :(

BuildTheRobots2• 12 years ago

Absolutely blown away with the demo video (centripetal issues aside) though annoyingly I'm one of those 'other' users, so I have to ask: Anything android related in the pipeline?

moinnadeem• 12 years ago

"This is one of the developers of the app. The Android version will be available in the following month. We are planning on running the experiment on Android devices too!" - OP.

sek• 12 years ago

Why not a GoPro on a wheel?

Edit: I just think I should've googled that first.

protomyth• 12 years ago

I would guess a GoPro doesn't allow Apps nor has the sensors accessible to perform the experiment with an external computer.

[edit] I do wonder why we haven't seen more programmable cameras with the sensors a smartphone has.

jonknee• 12 years ago

... Because this is an iOS app?

S4M• 12 years ago

...And it's interesting because?

ctdonath• 12 years ago

Because the focus of the experiment is an app that records videos while compensating for tilt/rotation (it's not just "hold muh beer while I tape my iPhone to a car wheel!"). I have the app, and find it interesting for its ability to eliminate the inevitable angling of the video, despite being on such an unstable mount (my free-waving hand). By subjecting the app to extreme conditions of rapid rotation, subtle flaws in the compensation process are made apparent - specifically, that the iPhone's gravity sensor gets confused & skewed, that the progressive scanning of each frame means distorting the image (the top of the image shows a view 1/60th or so of a second different from the bottom), and the two together result in a bizarre/unexpected periodic warping of the image. Having this video, the experimenters can go back to the software lab and tweak their image processing algorithms to compensate for these errors and create an even more stable image.

"So what?" you mumble. "It's so subtle nobody cares."

Well, that's actually a big part of why VR failed when it was first introduced a couple decades ago, and why Carmack & Occulus are so successful with it now: they've analyzed the subtle nuances that you don't acknowledge but your brain processes & reacts to nonetheless. Horizon is applying the same attention to detail, and will produce a better product as a result (yes, I do notice those sub-frame distortions in various products almost daily, and would appreciate developers correcting them).

zingermc• 12 years ago

I poked around the website and their projects look awesome, exactly the kind of stuff I'd make if I were more talented. I wish I lived in Greece because I would find these guys and beg them to hire me.

Goosey• 12 years ago

I found this to be really incredible. That is some amazing video stabilization technology. If this app was available for android I think I would use it for every video capture I ever do.

ProAm• 12 years ago

I'd love to see them film something while doing this. Maybe a dog or person running next to the car in frame or something. Definitely cool stuff.

petrakeas3• 12 years ago

This is one of the developers of the app. The Android version will be available in the following month. We are planning on running the experiment on Android devices too!

HorizonXP• 12 years ago

I've done quite a bit of work doing stabilization on Android. I think you'll find the Camera APIs quite lacking. Are you doing image based stabilization or using sensors? The fact you mention the gravity sensor tells me you're using sensors.

Let me know, I'll be glad to help how I can.

Kayou• 12 years ago

Did you see that it is only stabilizing rotation? If it looks so stable that's because the lens of the iPhone is at the exact center of the wheel. If you were to move your phone along a X or Y axis, I don't think those movements would be stabilized like you could get with a software stabilizer. I guess the main target of this app is people turning their device when shooting a video.

lutorm• 12 years ago

Translation of the camera changes the perspective, i.e., the relative positions of different objects in the image. There is no way a piece of software can get rid of that, because the information isn't there in the first place.

samstave• 12 years ago

I think they are using the middle-out algo for this.

kenjackson• 12 years ago

I found this to be really incredible. That is some amazing video stabilization technology. If this app was available for Windows Phone I think I would use it for every video capture I ever do.

(I'm really hoping for the same response that the Android guy got!)

btbuildem2• 12 years ago

Kudos to you guys for trying to solve the VVS problem! For your second experiment, may I recommend attaching the iphone to the disc of a variable-speed angle grinder? You'll get a much larger range of speeds, as well as the ability to aim the camera freely. You'll be able to test how your accelerometer algos handle pitch and yaw IN ADDITION to centrifugal force!

petrakeas3• 12 years ago

Developer of the app here. One step ahead of you ;)

http://imgur.com/tdnympM

askura• 12 years ago

I can't wait to see what that's going to look like. Just be careful it doesn't fly off and injure you!

jacquesm8• 12 years ago

I hope you're joking. If you do plan on doing this then please do it in a suitably strong wire cage, power it on remotely, make sure it is tied down very solidly and make sure nothing you care about (including you, significant others, co-workers, children, pets, possessions etc) is in the plane of rotation because this will fail spectacularly. Keep in mind that if the grinder becomes dislodged or unbalanced that the plane of rotation may vary rapidly. Too rapid to get out of the way. The iphone will desintegrate due to the forces involved and the shrapnel will cause serious injury.

Please do not do this unless you really know what you're messing with (and if you do then you won't).

On second thought, simply please do not do this. Spinning an iPhone up to 10K rpm or higher is a very bad idea, the label reads 11K rpm max, 850W, those things don't usually have soft-start so it'll just fire up and start throwing things.

Appeal to authority fallacy comes free of charge: I've had a pretty serious metal workshop and have seen several interesting interactions between angle-grinders and various objects in otherwise controlled circumstances, it is astounding how fast things can go wrong. Just having a grinder disc shatter on you can take you completely by surprise even if you know the danger, this is far more dangerous, it is Darwin award material.

columbo• 12 years ago

A box fan might be a safer alternative. It'd give you the ability to move it around but not the high rpm of a angle grinder.

btbuildem2• 12 years ago

Jesus Christ man I was kidding.. don't actually do it. Whatever you attach the phone with probably won't hold, and the phone will turn into a projectile traveling at high speed in a random direction. And if the phone does NOT come off, then you've got your hands on an unbalanced angle grinder going full tilt. Bad news bears all around.

userbinator• 12 years ago

Safety issues aside (as has been well-discussed by others already), the accelerometer won't report more than ~8G. Going any higher than that (which is not hard to do even with a moderately slow rotation) won't be very useful for testing out your app.

smallegan• 12 years ago

Bought the app, seems very laggy on my iPhone 5s. Is this to be expected? I wonder if it is doing the processing as the phone is recording or if it is capturing the accelerometer data and modifying the video after that fact?

uberspot• 12 years ago

It's doing all the processing on the fly while it's recording.

p00b• 12 years ago

Very cool experiment, and even cooler visual results!

One thing though - the tilting of the scene from the phone's perceived variance of the gravity vector is not due to centrifugal force, but due to inertia.

In other words, it's the same reason you're pushed back into your seat when you accelerate, and slam your head into the dashboard and spill hot coffee in your lap when you lock up the breaks.

petrakeas3• 12 years ago

We also did an experiment with this: http://imgur.com/tdnympM

The same problem existed. So it is not inertia in this case. However, inertia could also interfere with the gravity vector.

click170• 12 years ago

They kept mentioning 'Horizon', took me a couple minutes to realize they weren't talking about the BBC Series heh.

dested• 12 years ago

Now this is viral marketing. Great job guys

fooqux• 12 years ago

Does anybody know of any software which can do this for videos which were already captured?

mikeytown2• 12 years ago

http://www.guthspot.se/video/deshaker.htm http://avisynth.org.ru/depan/depan.html

spada• 12 years ago

will there be an API for this?

FollowSteph3• 12 years ago

Do NOT load from an iphone. Almost impossible to regain control of your browser!!

Goopplesoft• 12 years ago

Click url bar... Theyre using the new fullscreen api on iOS which kinda sucks IMO.

asciimo• 12 years ago

This looks like something that iOS will incorporate as a native feature. When they do this, do they usually buy the technology? Or the entire company?

vernie• 12 years ago

Or just clone it and put the company out of business.

placeybordeaux• 12 years ago

Is that really how apple has been working as of late? It's not like they innovate on the software front all the time.

porterhaney• 12 years ago

This would be similar to this acquisition IMO: http://www.macworld.com/article/2083997/apple-acquires-snapp...

return0• 12 years ago

Great job guys. Hope to see this integrated in the iPhone.

martin_• 12 years ago

It'd be really cool to see a side by side comparison with, and without Horizon active

sb23• 12 years ago

You can if you go to their website - http://www.evilwindowdog.com/horizon/

cratermoon• 12 years ago

That's nausea-inducing.

rodw• 12 years ago

What would happen if you put the camera closer to the outer part of the wheel, rather than nearly centered on the hub?

Could Horizon still create a stable-ish video out of that (where the position and rotation of the image are both changing rapidly), or does this require a relatively stable position to work this well?

(I have no particular dog in this hunt, I'm just curious.)

EDIT: I see that Kayou asked the same question, probably in a smarter way, here: https://news.ycombinator.com/item?id=7904992 but I don't see a response from petrakeas or stelabouras yet, so I'll keep my question here even if it is a little redundant.

stelabouras2• 12 years ago

Horizon corrects the wrong orientation regardless of the translation/position of the device. Small translation differences along the X or Y axis can be corrected by the stabilisation algorithm. Large translation deltas, however, cannot be corrected.

So, if you put the iPhone on the outer part of the wheel you will most probably get a horizontal video that will end up showing your scene moving up-down, left-right.

ar_turnbull• 12 years ago

A roller coaster might be a good experiment if you're looking for an extreme environment that might appeal to more of a mass market. (http://en.wikipedia.org/wiki/List_of_roller_coaster_rankings) Maybe skydiving or bungee jumping?

Or you could go a different direction and attach a phone to a cat. I hear people love videos with cats ;)

frozenport• 12 years ago

Phones falling off a roller-coaster could be dangerous!

Show HN: We put an iPhone on the front wheel of a car

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