问题
I want to use an UIImagePicker to have a camera preview being displayed. Over this preview I want to place an overlay view with controls.
Is it possible to apply any effects to the preview which will be displayed from camera? I particularly need to apply a blur effect to the camera preview.
So I want to have a blurred preview from camera and overlay view with controls. If I decide to capture the still image from the camera, I need to have it original without blur effect. So blur effect must applied only to the preview.
Is this possible using such configuration or maybe with AVFoundation being used for accessing the camera preview or maybe somehow else, or that's impossible at all?
回答1:
With AV foundation you could do almost everything you want since you can obtain single frame from the camera and elaborate them, but it could lead you at a dead-end applying a blur on an image in realtime is a pretty intensive task with laggy video results, that could lead you to waste hours of coding. I would suggest you to use the solution of James WebSster or OpenGL shaders. Take a look at this awesome free library written by one of my favorite guru Brad http://www.sunsetlakesoftware.com/2012/02/12/introducing-gpuimage-framework even if you do not find the right filter, probably it will lead you to a correct implementation of what you want to do. The right filter is Gaussian blur of course, but I don't know if it is supported, but you could do by yourself.
Almost forgot to say than in iOS 5 you have full access to the Accelerate Framework, made by Apple, you should look also into that.
回答2:
From the reasonably limited amount of work I've done with UIImagePicker I don't think it is possible to apply the blur to the image you see using programatic filters.
What you might be able to do is to use the overlay to estimate blur. You could do this, for example, by adding an overlay which contains an image of semi-transparent frosted glass.
来源：https://stackoverflow.com/questions/9466502/blur-effect-in-a-view-of-ios