

Unsupervised Billboard Detection - madhkrish
http://tech.adstruc.com/

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Agustus
A great article. This is what Hacker News should be about; identifying a
problem, researching solutions, and publishing the results for use. Thank you
for a fantastic post.

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chrisdroukas
Watch Google incorporate this into Street View to deliver billboard
advertisements.

~~~
andrewjshults
They actually filed a patent in 2008 to do that
[http://www.readwriteweb.com/archives/google_could_soon_augme...](http://www.readwriteweb.com/archives/google_could_soon_augment_old_billboards_in_street.php)
(direct link to the patent: [http://appft.uspto.gov/netacgi/nph-
Parser?Sect1=PTO2&Sec...](http://appft.uspto.gov/netacgi/nph-
Parser?Sect1=PTO2&Sect2=HITOFF&u=/netahtml/PTO/search-
adv.html&r=2&p=1&f=G&l=50&d=PG01&S1=google.AS.&OS=an/google&RS=AN/google) )

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elviejo
This is great. I wonder if applying a crowdsource solution, with humans
selecting the billboard, would also have delivered a cost-effective solution
with the benefits in less time.

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andrewjshults
This is actually something we considered (we originally built this tool to
import data from one of the major vendors). Their data was consistent enough
that we were able to achieve a high enough hit rate, that it made sense to do
it this way (OpenCV is an amazing framework for this type of task). However,
from most of our vendors, the board themselves are not outlined/blocked out.
In those cases, the CV algorithms fall apart fairly quickly, since quality of
the input photos is quite variable (most are rather low resolution and you'd
be surprised at the number of images we get with trees or other objects
blocking a large portion of the board). The crowd sourced version is
definitely on our fun tasks pile, since we've got a lot of inventory identify
the bounds automatically.

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parkan
Kind of surprised that the first comment isn't about automatically occluding
these with google glass (yes, I know you can't fully paint over it
[http://blogs.valvesoftware.com/abrash/why-you-wont-see-
hard-...](http://blogs.valvesoftware.com/abrash/why-you-wont-see-hard-ar-
anytime-soon/))

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wpietri
Next up: a car, running this in real time, with an automated paintball
launcher. Anybody got a good project name?

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shimon
AdBlock Prius

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njharman
I'm eagerly awaiting "They Live" mode.

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ajays
I'd like to see how it works on the third image from the top, with the gas
station sign, etc.

It is fairly straightforward to detect a billboard in a random nature scene;
look for straight lines and intersections of them. Most (all?) billboards are
also horizontal.

It is quite another thing to detect billboards in an urban setting.

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madhkrish
I've added the output at the end of the blog post for that image... check it
out!

This algorithm works pretty well for billboards in urban settings as well --
since the photos come with the units outlined.

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danso
Ah, this post makes me doubly excited about how I got OpenCV (+ the Ruby
wrapper) to successfully install on Mountain Lion.

