It is necessarily encoded. Othwise you would not be able to see it.
Explain. I see the rock in my hand because photons of certain wavelengths are reflecting off of it and stimulating certain cells in my eyes. This begins a electro-chemical cascade through my optic nerves to my brain where further electro-chemical cascades in neurons allow me to identify it. There is no magic "code" only electro-magnetism and electro-chemistry involved.