CIFilter output image nil

Question

I am using core image and I am applying a CIFilter sepia tone to my image. I run a filter once in viewDidLoad and then immediately call another function that adds the filter

Answer 1

You cannot call UIImage(CIImage:) and use that UIImage as the image of a UIImageView. UIImageView requires a UIImage backed by a bitmap (CGImage). A UIImage instantiated with CIImage has no bitmap; it has no actual image, it's just a set of instructions for applying a filter. That is why your UIImageView's image is nil.