Canon PIXMA MG5500 series Online Manual page 140

Note
The Skew Correction function automatically compensates for the originals placed at an
angle of up to approximately 10 degrees. Slanted photos with a long edge of 7.1 inches
(180 mm) or more cannot be corrected.
Non-rectangular or irregular shaped photos (such as cut out photos) may not be
scanned properly.
140