Canon PIXMA MG4200 Series On-Screen Manual page 752

Adjust cropping frames
You can adjust the scan area in preview.
If no area is specified, the image of the size selected in Select Output Size will be saved. If an area is
specified, only the image in the cropping frame will be scanned and saved.
Adjusting Cropping Frames
Save
Save
Saves the two scanned images as one image.
Cancel
Cancels Stitch scan.
(2) Toolbar
Toolbar
You can delete the scanned images or adjust the previewed images.
(Cancel)
Deletes the scanned image.
(Enlarge/Reduce)
Allows you to enlarge or reduce the preview image.
Left-clicking the Preview area enlarges the displayed image.
Control-clicking the Preview area reduces the displayed image.
(Rotate Left)
Rotates the preview image 90 degrees counter-clockwise.
(Invert Vertically)
Rotates the preview image 180 degrees.
(Rotate Right)