ABBYY FineReader 12 Professional (the lower-priced version) will process multiple image files in the same folder in the same process if they are selected when the 'Open' button is used...arpadlabadi wrote: ABBYY did a great work. However, one drawback of ABBYY FineReader 12 Professional (£99 GB Pounds on amazon.co.uk) is that it does not support batch OCR/conversion of multiple files. I think this feature is very important for those scanning books, and not only archiving single documents. So in order to get this feature - as far as I understood - one should buy the ABBYY FineReader 12 Corporate Edition (a single license costs £149 GB).
The batch processing in the Corporate Edition would only be required if it was desired to process multiple folders of images to produce multiple output files as a single operation.
On the detail of the image quality, manual adjustments can be made in ABBYY if the 'Edit Image' button is pressed, and the 'Brightness & Contrast' and 'Levels' adjustments would be worth exploring. However, a better first step as you recognise might be to try to improve the quality of the source images, both the colour balance and the evenness of the illumination. The evenness of the illumination sets a limit to the enhancement that can be obtained using 'Levels', for example to minimise bleed through from the other side of the page.
The 'Photo Correction' adjustment includes a 'Whiten Background' control which is probably the first enhancement to apply, and that enhancement and some others can be automatically applied to all images using the 'Options' > 'Scan/Open' tab.