Avision Multifunction Scan Center User Manual page 96

The resolution is measured in pixels per inch (ppi) (sometimes
Resolution
referred to as dots per inch or dpi). Higher resolutions result in
more detail in the scan, slower scanning and in general, greater
file sizes. For example, an A4 size color image scanned at 300
dpi with color mode consumes approximately 25 MB of disk
space. When OCR (Optical Character Recognition) is to be
performed on a scan, 300dpi should be used for most
languages except Asian languages. For Asian languages, 400
dpi is recommended.
Choice: 75dpi, 100dpi, 150dpi, *200dpi, 300dpi, 400dpi,
600dpi.
Lighten or darken the image by adjusting the brightness slider
Brightness
right or left.
Choice: Level1~7. Default value: 4
* Factory Default
Resolution: 75 dpi
Brightness: 1
Resolution: 150 dpi
Brightness: 4
(Normal)
90
Brightness: 7