Quest - while layout-by-layout loading may help, I'm afraid part of the problem is what you have described is just about the worst possible way you could design your game from a memory use point of view.
A single image at 2048x1536 will take about 12mb of memory. Having 30 of them will take around 350mb of memory! That's so much even some desktop computers will have problems dealing with that, let alone mobile devices.
You need to design your game differently for it to work well on mobile. See the manual entry on best practices:
b]Memory use
Some designers are tempted to design entire levels as single large images, for example 10,000 x 10,000 pixels. This method should be avoided at all costs. Not only is this extremely wasteful on memory, many devices also do not support images above a certain size, meaning your game does not work at all for many users. Generally the largest image size supported on all systems (including mobile phones) is 2048 x 2048 pixels. You should still avoid using images this size; a far superior way of designing levels is to use a few medium-sized Tiled Background images (e.g. 512 x 512) to cover the layout, then compose the level design from placing multiple instances of other Tiled Background and Sprite objects. Each instance can be freely stretched and rotated individually which can help avoid a repetitive appearance.
Consider a single 10,000 x 10,000 image will use 400mb of memory, which will make all but the most powerful desktop computers run out of memory. On the other hand, a level composed of three 512 x 512 Tiled Backgrounds and 50 different Sprite objects sized 200 x 200 will use under 20mb of memory (20x less) - small enough to fit in to the memory of low-power mobile phones.