\begin{definition}[Definition:Image/Also denoted as]
The notation $\Img f$ to denote the image of a mapping $f$ is specific to {{ProofWiki}}.
The usual notation is $\map {\mathrm {Im} } f$ or a variant, but this is too easily confused with $\map \Im z$, the imaginary part of a complex number.
Hence the non-standard usage $\Img f$.
Some sources use $f \sqbrk S$, where $S$ is the domain of $f$.
Others just use $\map f S$, but that notation is deprecated on {{ProofWiki}} so as not to confuse it with the notation for the image of an element.
\end{definition}