Ricoh is01 Betriebsanweisung

The auto photo/letter mode detects photograph (halftone) areas and
letter (binary) areas of the original so that the binary areas are
scanned in the binary mode, and the halftone areas are scanned in
the halftone mode.

Note: This function is available only when the optional image

processing unit is installed in the scanner. When binary areas
and halftone areas are not separated clearly, segmentation
may not be achieved.

Scanning of an original that includes binary images such as letters
and halftone images such as photographs.

Original

Scanned image

Scanned in halftone
composition

Scanned in binary
composition