I have some doubts about the dimensions of images
If your deployment target is
ios 7 and later then you require two launch images
1x and 2x of size
768 x 1024 pixels and 1536 x 2048 pixels respectively for
portrait and vice versa for
landscape for ipads!
You can easily know this from
attributes inspector - expected size after clicking any
1x or 2x image from
And You not require 3x image for ipads!