Total Image Slicer can slice, merge & convert your images. Extremely easy-to-use. For example, you scanned a book and got a double-page spread of PDF format.
Image Slicer will help you at one time to slice the file into two separate pages and convert to the format you need (JPEG, PNG, BMP, TIF, GIF, PCX, TGA, or leave it as it is in PDF).
The tool allows you to slice images to specified size or to a table (you set the numbers of rows and columns all of which will be of the same size).
But that is not all. Image Slice can also merge images. Just select the images, press Merge button and set the number of images per width and per height. When dealing with JPEG files, you will be able to define quality or smoothing.

The license of this software is Free Trial Software, the price is $19.90, you can free download and get a free trial.