Earlier quoted context omitted.
But the physical space?
3840 × 2160 Total number of pixels = 8,294,400 log2(8,294,400) ≈ 23 (each additional bit doubles the number of unique addresses that can be represented) so 24 bits are the minimum required to locate a point in 2-d space at the resolution of "4k". when you add in color, 60 bits per pixel. 19 bits for 640x480.
Is it possible to think of something as a quarter bit with rgba