Application draw highest resolution for image from xcassets

I need to show image programatically, so i do something like

[UIImage imageNamed:@"image"];

But this method always return image, which resolution is higher, than needed. So i run under 5s, but image is for @3x etc.

I set my launch screen: http://ift.tt/1EeMtdZ ,but it's always @3x show when it's don't need and in fact i have 3 pics, it's:

2x - title1136@2x.png, 327 × 165 pixels ,@2x scale
Retina 4 2x - title1334@2x.png, 382 × 193 pixels, Retina 4 @2x scale
3x - title2208@3x.png, 635 × 321 pixels, 3x Scale

There are parameters for one image pack from xcassets. I want to show this image on 5s - @3x on screen. I want to show this image on 6 - @3x again on screen. That's a problem, i don't understand how to show on 5s my 327*165 image, on 6 382*193 and on 6+ 634*321.