well I wrote much to describe CPU and it may seems complicated and messy, but just
play with it and you'll get it quickly.
Start simple :
autocrop one image :
cpu --filters autocrop pic1.jpg
or with short options :
check doc of autocrop :
cpu --filters autocrop=help (cpu -f a=h)
Imagine you want to crop borders more : option to filter is given this way :
cpu -f a=50 pic1.jpg (default value was 64)
Then you can do this on all your pics :
cpu -f a=50 pic1.jpg pic2.jpg pic3.jpg pic4.jpg pic5.jpg
I guess you can also use wildcards for many files or just use the .bat I provided
and customize it with your options and then just drag/drop all your files on it.
Let's imagine you have double page scanned.
You might want to split them first in single pages, then you would like to autocrop each
single page :
cpu -f splitpages,a <all_pics>
You may also want to see what it gives by cropping first double pages and then split them :
cpu -f a,splitpages <all_pics>
but this will all work without changing colors, and if you need them in gray, let's say 16
levels of gray (=2^4, default is 2^16) then you'll add this filter after all the previous ones :
cpu -f s,a,grayscale=4 <all_pics>
You also want that this fits on your screen reader :
cpu -f s,a,fitpage,g=4 <all_pics>
and if it's not a prs505 (default size), say a 800x600 screen :
cpu -f s,a,fitpage=800:600,g=4 <all_pics>
There are other filters like "gather" which are more advanced and other options too that
are not needed for simple use, but this was a quick how to start.
I hope you'll find what you need