I need some guidance that how to capture the face when we blink the eyes. I have seen the core Image framework, but it detects only after capturing the image. But I need it to be live capture.
The only way to know if the user blinked is to capture an image then analyze it.1
You'll probably have a loop
begin loop capture an image analyze image if user is blinking do something with image else discard image end if end loop
According to Wikipedia, people blink every 2 - 10 seconds (or less, when reading) and blinks last a around 100ms or so. You'll have to figure out how often you need to capture an image to get a good chance of capturing a blink.
My guess is that you'll probably capture and throw away a lot of images before you get the one you want.
1 I suppose you could use a sensitive microphone and listen for a blink, but that's silly. Better to stick with capturing a lot of images and analyzing them.