Zoom into a very large image(z-fighting problem)

I am making a game for Android where I need to zoom into a very large image(4000x3000) I use sprites because it's a 2d game and I want to keep the texture size to 1024(safe size?).

I divided the 4000x3000 image to many 512x512 images and create textures of them in runtime and put them next to each other.

The problem is z-fighting occurs between the 512 images. I tried:

• setting different z values and sorting orders for 512 images

• playing with camera(orthographic) near and far clipping panes

• making the 512 images overlap some pixels

Also, is this the right way of zooming into a very large image??

Screenshot: