Divide a scanned image containing multiple photos
If you scanned several pictures at once on a flatbed scanner, you can automatically divide and straighten the scanned image into its component photos. The photos must have a clear separation between them.
Separating images scanned from one page into three separate
images
Choose Image > Divide Scanned Photos. Photoshop Elements automatically divides the image
and places each photo in a separate file.
For images with white around the border
(images of light skies, snow, and so on), this command works best
if you cover the image on the scanner with a piece of dark paper.