The Deprecation of presentModalViewController:animated: in iOS 6: A Guide to Programmatically Presenting View Controllers

Thread Safety in iOS Image Processing: Best Practices for Creating Images on a Background Thread

Here's the complete example of how you can put this code together:

Removing Borders from UIPageViewController Images Without Losing Page Indicators Effect

Alternative to UIImage's imageWithCGImage:scale:orientation: A Step-by-Step Guide

Animating Image Changes in UIImageView