Axel Etzold wrote:
> Dear all,
> 
> I have a number of black-and-white scanned pages. To prepare them for OCR,
> I have to split them in columns and rows. Additionally, somewhere in between, there
> are pictures, which also need to be separated.
> 
> So, in a page that might look like this:
> 
> Text1 Text4 Text6
> 
> Text2 Pict1 Text7
> 
> Text3 Text5 Pict2
> 
> I'd like to find the largest blocks of white which separate the texts and pictures, both horizontally
> and vertically.

Anthony, one of the IM team, has a suggestion you can read here: 
http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=11980&p=39232#p39232. 
If this is something you want to pursue let me know and we can work on 
converting his shell script to Ruby.

-- 
RMagick: http://rmagick.rubyforge.org/