I agree that de-interleaving is fairly complicated, but interleaving can be done fairly easily with a lookup from a table for each dimension and then combining

I agree that de-interleaving is fairly complicated, but interleaving can be done fairly easily with a lookup from a table for each dimension and then combining them: xbits[x] | ybits[y] | channelbits[c]. The nice thing about this is that just by changing the tables, you can get things like z-curve, tiles, row-major, or column-major pixel orders (or even combinations), plus swizzled, interleaved, or planar layouts for the color channels.