title: Image Sizes in iOS
body: <p>I have a question about assets. When I have an image that has to be half of the screen, how many image files do I need? 
  For the iPhone 5 I need @1x, @2x and @3x; for the iPhone 6 I need @1x, @2x and @3x; for the iPhone 7...</p>
  
  <p>This is the right way? If that the case, I will have to get the size of the device through code and then, depending of the size, use the right image?</p>
  
  <p>If this is not the right way and I have to make a unique image in PDF from with single scalable image, what should be the size  in pixels (width and height) for that image.</p>
  
  <p>This is something I am struggling with, because it is different from using fixed images where all I need is @1x, @2x and @3x for all the devices</p>
  
  <p>Thanks a lot for your time!</p>