In Interface Builder, use the following configuration:

There are two important settings, namely:
-
Mode: Aspect Fill -
Clip Subviews
It can also be done programmatically:
[imageView setContentMode:UIViewContentModeScaleAspectFill];
[imageView setClipsToBounds:YES];
This will correctly fill the view with the image, keep its aspect ratio and hide what doesn’t fit.