Brother MFC-7820N - Manual (Page 107)

Using your machine with a Macintosh ®
7 - 30
7
Scan to Image:
In General tab
You can enter up to a 30 character name in the Name for
Custom field. This name will appear as the button name.
Select the type of scan from the Scan Action field.
In Settings tab
You can select Target Application, File Type, Resolution,
Scan Type, Document Size, Brightness and Contrast
settings.