Avision AD215L, User Manual, Page: 51 / 136

42
Gray
Document Type: Choice: Normal, Photo, Document
Three options of document type are provided when you choose
Gray as the image type for your scanned document. Choice:
Normal, Photo, Document.
 Document: Choose Document if your original contains
pure text or a mixture of text and graphic since it is an
optimal setting for regular business document. When
using Document, only Threshold can be adjusted.
 Photo: Choose Photo if your original contains photo to
reproduce your photo in vivid grayscale image. When
using Photo, no Threshold and Contrast can be adjusted.
 Normal: When using Normal, Threshold, Brightness, and
Contrast can be adjusted.
Threshold: The value ranges from 0 to 255. The default is
230. A low threshold value produces a lighter image, and can
be used to subdue backgrounds and subtle, unneeded
information. A high threshold value produces a darker image,
and can be used to help pick up faint images. Adjust the
threshold setting by dragging the Threshold sliding bar to the
left or right to achieve the desired threshold setting.