http://www.b4x.com/b4i/help/drawing.html#bitmap_initialize
The iPhone 6 screen non-normalized scale is 2.
The iPad non-normalized scale is 1.
The logical scale on all devices is 1. This is different than Android and this is why the 'dip' unit is not required in B4i as in B4A.
Lets say we have an image named image.png with the size of 100x100.
This means that when you load this image on iPhone 6, the image will not be super sharp as it is actually mapped to 200x200 real pixels.
So you can add an image named
image@2x.png with the size of 200x200.
You should still load image.png however on a high resolution device
image@2x.png will be loaded instead and its size will be 100x100 (because we are working with scaled pixels).
A message will be printed in the logs saying that the @2x image was loaded.