There is absolute such as thing as a 1d image, in many disciplines.

(+ the meaning in math as what comes out of a function....)

There are even 1D cameras - e.g. scanners, finish line cameras for races, some old barcode scanners (although most can do 2D now and even those that only support 1D barcodes might make use of a 2D camera).

> "2D image" is still useful, to distinguish from 3D.

No it isn't? You don't say "here's that 2D image you wanted" when you send someone a jpg.

still useful in contexts like the one it was used in upthread, which was not "when you send someone a jpeg".