Scanning multiple pictures, then automatic cropping

There is a new ImageMagick Script that does exactly what you are asking here:

Photoshop Elements can automatically divide a scanned picture into subpictures.

Too bad your scanner didn't come with the software, but I've seen scanners come with software to divide pictures and even do corrections like if there were wrinkles in the pictures.

A similar was question asked in the ImageMagick forum, from what i gather, they only came up with a solution for single images, worth reading anyway:

auto-crop multiple old photographs from scanned image?