

Ask HN: How to do face recognition - petervandijck

If I'm building an iphoto-like app online, how can I get my server to do face recognition (recognize where a face is in a photo, and also recognize who (of your limited set of friends) this face might be)? It seems pretty simple if even cheap cameras do the first part, and most photo software does the second part quite well.<p>Is there an open source or commercial package we can get? An API? Are the algorythms easy enough to implement something like this in a month or so?
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Jun8
You seem to be new to the topic since you are confusing face detection and
face recognition. Face detection is a relatively simple affair, given an image
determine a bounding box for each candidate face. OpenCV
(<http://opencv.willowgarage.com/wiki/>) is an excellent library with a lot of
computer vision related functions. Out of the box it has an example program
for face detection which performs quite well with the default Haar model files
it comes with. Detection rates of higher than 95% are not uncommon for photos
with clean faces. So, you can set up a fairly good face detector in a day or
so.

Face recognition, on the other hand, is a totally different beast. The
bounding boxes you detect in the detection step are fed into classifiers that
you should train. If you are new to this field I don't recommend you do this
training or develop your own algorithms, since it's a complicated problem. You
say most photo software does this, but generally these are offerings from
large companies, e.g. Picasa, that have _years_ of face recognition expertise
behind that product. My recommendation is (i) to abandon the recognition idea
(gulp! this may be hard to stomach but the energy may be better spent
somewhere else, as this is very hard to get right) or (ii) if you insist, use
an online API (e.g. <http://developers.face.com/docs/>).

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st3fan
I have some history with Polar Rose. They are currently licensing their Face
Detection and Matching engine. Either as a web service or as a library that
you can include and use directly on your own servers.

<http://info.polarrose.com/solutions.php>

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petervandijck
<http://developers.face.com/docs/> has anyone used that? Any good?

~~~
edens
try it, it has a sandbox where you can try detect / train / recognize API
calls.

(full disclosure, I'm a co-founder @ face)

