Canon imageFORMULA R40 User Manual page 42

Select the [Text Orientation Recognition] check box. The text
orientation on each page is detected, and the scanned image is
rotated in 90-degree increments to correct the orientation.
Hint
When the [Text Orientation Recognition] check box is selected,
[Document Orientation] is unavailable.
When you want to rotate the images of a document placed
horizontally to correct the orientation
Specify the rotation angle in [Document Orientation] on the [Others]
tab.
Click [Image processing] and specify the rotation angle in [Document
Orientation] in the dialog box that appears.
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