Is there a name for this method of writing that includes pictograms?

I've seen people write (usually in a humorous way) a 'code-like' message where parts of words are replaced with a pictogram that sounds like that word-part. E.G.:

(eyeball) (tin can)(rope knot) get the (hole in ground) (earth) in my head, yet.

becomes

I cannot get the whole world in my head, yet.

I once saw this used in a fictional book, and wonder if it has an actual name.

Edit: the answer also helped by re-find this wonderfully imagined race that communicates via rebuses.

This is called a rebus:

A rebus is an allusional device that uses pictures to represent words or parts of words. It was a favourite form of heraldic expression used in the Middle Ages to denote surnames, for example in its basic form 3 salmon fish to denote the name "Salmon".

Here is an example:

It is called a rebus.

a puzzle in which words are represented by combinations of pictures and individual letters; for instance, apex might be represented by a picture of an ape followed by a letter X.