How can I avoid or remove shadows along the edges of scanned images?

The shadows along the edges can be partly avoided by placing a white A4 paper into the Carrier Sheet as a background of the document to be scanned.

If you prefer, you can trim the scanned image to the desired size by PDF editing software such as Adobe® Acrobat® or Kofax® Power PDF.

Adobe® Acrobat® 8 or 9:
Navigate to the menu bar > [Tools] > [Advanced Editing] and select [Crop tool] to launch the crop tool. Select an area to crop and double click the area to trim the image.

Adobe® Acrobat® X or Xl:
Navigate to the menu bar > [Tools] > [Advanced Editing] and select [Crop tool] to launch the crop tool. Select an area to crop and double click the area to trim the image.

Kofax® Power PDF:
Navigate to the menu bar > [Edit] > [Crop] to launch the crop tool. Select an area to crop and double click the area to trim the image.