Apple’s iOS 5 will have built-in facial recognition capabilities. Better yet, Apple isn’t planning on simply using the technology to power a single feature. Instead, it will release it as an open API for developers, bringing easy integration of face recognition to the App Store.

9to5 Mac put the pieces together, finding that Apple has put to use the 2010 acquisition of Swedish facial recognition algorithm specialist Polar Rose. While it sounds like the name of a Sting album, Polar Rose has an impressive portfolio of developments, including Recognizr, a social media linking app co-developed with TAT that recognizes users and displays their network profiles on-screen. Check out the demo video below.

The tech is already available in OS X Lion as Photo Booth, which uses facial recognition to accurately manipulate user’s photos into all kinds of wacky final products. The feature has been included in all manner of Windows webcams and whatnot for awhile now, but has only just trickled over to the Apple ecosystem. It’s unclear if Apple with bring Photo Booth itself over to iOS, but once the API is released to developers, expect photo manipulating apps to blossom into flashlight app-like numbers.

9to5 Mac dove into the APIs, and found two related to the Polar Rose technology. One, called CIFaceFeature, can determine where a person’s mouth and eyes are on a photo. The second, CIDetector, is an operating resource for that “processes images for face detection” which possibly would be used for video.

So what’s it all mean? Photo manipulation aside, Recognizr shows off a likely route facial recognition will take. Using your face as your business card and link to online profile is more instant than other methods, and is great if your name is hard to spell. Of course, it’s also cause for privacy advocates to start chattering. Although using facial recognition software to glean information off someone will be limited to whomever lists their profile with a service like Recognizr (until Facebook decides to get involved), it does open up a new avenue for privacy discussion that Apple is going to have to deal with as they prep to launch the iPhone 5.