Firstly, the texture will need to split up, its too large. Max texture size for 3GS and above and iPad is 2048x2048. If you want to support lower iPhones then you will to split into 1024x1024 chunks. You could write some code but the simple way is to manually split the image, and spread it across several planes.
There are plenty of posts about getting a pixel perfect orthographic display… simplistically you just need your camera size to be set such that your objects height of 1024 exactly fills the whole display. A little searching should help you with that.
You will also want to ensure that your objects are not using mip maps and are imported with an accurate colour representation (choose the advanced option in the texture importer for lots of options).
thank you for your answer, I think I found something and I will try to use it.
I’ve still another question.
Since I have an Cylinder with this texture (picture)
Is it possible to insert more than one picture in different positions on this cylinder.
In blender i Can create vertices groups and apply different texture for each vertice group, work that also in Unity? so I can have more than a Picture as texture with less than 1024 pixels?
Actually it will work. If you apply different textures to different vertices in Blender, then it comes in as an object with multiple materials in Unity.