[plopz]

When you say you encode different values in rgba channels, are you actually saving the rasters as image files then?

[zhdc1]

The previous poster is likely referring to something like a GeoTIFF, which more or less accepts an arbitrary number of bands (matrices).

[ungawatkt]

Yep, for my purposes I tend to use pngs for simplicity, but the next step would be GeoTIFF