Use pdf Images in iOS
Mainly, We are using the png images for icons to set in our application. When we set icons it will look different in iPhone 5s , iPhone 6 , iPad. To recover from this issue we use the three types of images with scale @1x, @2x, @3x ,But this is not a good way to use the three images for your icon.It will Increase your Application size also. You can use the pdf vector images (http://martiancraft.com/blog/2014/09/vector-images-xcode6/ , http://useyourloaf.com/blog/creating-scaled-images-with-pdf-vectors/) use these links to create your pdf image after creating pdf image use following steps :-
1: Open xcode.
2: Go to assets.
3. Click on add new assets.
4. Add your pdf image or drag and drop the pdf image.
5. On the right side change the scale (universal to single scale).
6. Now you can use the image as assets name anywhere in your Application.