Deal to slow about uiimageview-betterface

[croath]

@Yi-Chen1 did you mean how to deal with the slow speed of rendering images?

In fact there is a way to increase the speed which I recommended it in the readme:
try set the fast property to YES to get the faster speed(lower accuracy)
Have you try it?

[croath]

@Yi-Chen1 How many imageviews you need to show at one time? And what's the average size of these images?

I think I should move detecting code to an async thread and then go back to main thread to render.

[croath]

@Yi-Chen1 I've push something to master will you pull to try it again?

And as you said, it may be not so smooth if there are 3 pics in one cell (may be 500px*500px of one?), beacuse face detecting of iOS SDK won't be that fast as you imagine.

So if the latest push can not satisfy your needs, try using UIImage+BetterFace, the UIImage category.
By using it you might make another cropped image after downloading, and cache it yourself 😭

[croath]

@Yi-Chen1 Is your problem solved?

[neoplastic]

I've requested a merge for this. It looks like your original code was creating a new CIDetector each time you set an image. This looks damn simple in code but in actuality its creating a new CIContext inside the GPU thus competing with UIScrollView. Give the new code a shot and see if your performance improves. Although its still not 60fps as I'd have liked!

[croath]

@neoplastic

Is that the main reason that makes it slow?
I don't think so, in my test the detecting method is the most slow step.
I don't know how much time it will save, I'll give it a try.

[neoplastic]

You need to setup a scroll view with lots of images on it. Here's an apple reference for CIDetector reuse.

"This class can maintain many state variables that can impact performance. So for best performance, reuse CIDetector instances instead of creating new ones."
http://developer.apple.com/library/ios/#documentation/CoreImage/Reference/CIDetector_Ref/Reference/Reference.html

Although its not the only reason its slow, its the main reason its slow when implementing it in a scroll view. At least that's what I've found.

[croath]

@neoplastic but in your pull-reqeust, it's also creating a new one at most time. How about using a singleton instance of CIDetector?

[croath]

merged, should be closed.