Microtek 1000xl 参照マニュアル

C. Prescan Image Margin

This option allows you to specify how wide or narrow the margin around the
scan frame is for the prescan image. Options are: Minimal, Small, Medium, and
Large. Smaller margins give you more room to capture the preview image, while
larger margins will allow you to have more room to expand your scan frame.

This is helpful because selecting the exact scan frame (through the Scan Frame
tool) can never be a completely accurate process, and what appears to have
been selected by the scan frame when you view the image in the lower-
resolution overview may or may not actually include the portion you wish. The
margin — depending on how wide or narrow it is — can then provide a berth or
allowance for extending the boundaries of the scan frame around the prescan
image. Margin options include minimal, small, medium, and large.

D. Prescan Image Dimension

This option lets you specify how large the prescan image will be: Full screen
("screen" meaning your main monitor), 75% screen, 50% screen, and Fit
Preview Window. The larger the size, the higher the prescan resolution. The
maximum prescan resolution is the scanner's optical resolution.

E. Background Prescan

If checked, the background prescan function is enabled. You can assign a
number of scan jobs to execute a prescan while carrying out other jobs in the
meantime (e.g., performing color correction to other scan jobs). If unchecked,
this function is disabled.