Speedup ios-realtimeblur ( by factor of 2-3! )

[robertjpayne]

The performance of this library could be greatly improved, below is a list of recommendations to take to increase the performance:

• To capture the raw pixels you can utilise a CGBitmapContextCreate with your own memory buffer as the first argument. This allows you to skip compressing it to a JPG and then an NSData object just to unpack it back into raw pixels using the image provider methods.
• You can use the vImage_Buffer as both the source and destination to avoid using more memory than necessary.

Both of the above recommendations can be found here: https://gist.github.com/robertjpayne/6775157. I didn't create a pull request because the code is not heavily tested.

In the simple testing I did it resulted in a speedup of about 2-3x.

[carlinyuen]

Have you done more testing on this perhaps? Interested in seeing this change go in to make things more performant on iOS 6 devices.