Scanning the images and documents is a simple job but it does call for some guidelines to ensure that the scanned images and documents come out the way you want them to. For instance, placing the document/photograph in the flatbed scanner can also influence the final output. Most of modern scanners are intelligent enough to correct any accidental placement errors. Many of us don't align the pages properly, so some scanners have incorporated a feature to correct misalignments automatically.
However, the auto correction feature in most scanners works only to a certain extent. The pages/photos that are just slightly skewed on the scanner bed are corrected. If your original is tilted by more than degrees, the scanner assumes that you intentionally put it that way. So don,t assume that all the scans will be corrected irrespective of the placement, and try scanning the document or photo again.