Canon 4204B019AA User Manual page 540

Scanning Resolution
Set this item using the Operation Panel of the machine.
Recommended Image Correction
Select this checkbox to apply suitable corrections automatically based on the document type.
This function is available when Document Type is Auto Scan.
Important
When this checkbox is selected, the files can be saved in JPEG/Exif or PDF format only.
Scanning may take longer than usual when this checkbox is selected.
This function is not available when scanning by pressing the Black button with Auto Scan
selected on the Operation Panel of the machine.
The color tone may change from the source image due to corrections. In that case, deselect the
checkbox and scan.
Descreen
Select this checkbox to reduce moire patterns.
Printed photos and pictures are displayed as a collection of fine dots. "Moire" is a phenomenon where
uneven gradation or a stripe pattern appears when such photos or pictures printed with fine dots are
scanned. Descreen is the function for reducing this moire effect.
Note
Scanning takes longer than usual when you enable Descreen.
Unsharp Mask
Select this checkbox to emphasize the outline of the subjects and sharpen the image.
Remove gutter shadow (Platen) / Remove gutter shadow
Select this checkbox to correct shadows that appear between pages when scanning open booklets.
When Document Type is Photo, the checkbox changes to Remove gutter shadow.
Important
This function is available only when scanning from the Platen.
Align the document correctly with the alignment mark on the Platen.
Note
Use ScanGear (scanner driver)'s Advanced Mode tab to correct gutter shadows when scanning
non-standard size documents or when custom cropping frames are set.
For details, see Gutter Shadow Correction in "
Reduce Show-through
Select this checkbox to sharpen text in a document or reduce show-through in newspapers.
Note
Select this checkbox if show-through is apparent when you scan documents.
Text Document Handling
Image Settings " (ScanGear's Advanced Mode tab).