I think the OCR Export and Import feature with the md5 hash as file names is a good one, and also usefull for graphical images.
In several cases scanned documents are very important. As said, pdf and Tiff formatted files, contain text in most cases. So doing OCR is not the question (you should do this always in my opinion).
JPG is also a file format that is used for scanning output. OCRing all the pictures in a case won't work, because of the very time consuming process.
We do a little handwork by exporting all the images (except tiff, because we already do Tiff in our main process) and name them by the md5 hash (same as OCR export). After exporting we do a manual analysis by viewing the images in a thumbnail view, with f.i. Microsoft Office Picture Manager or Acdsee, IrfanView and others. First sort the pictures on the file size. Smaller files are mostly not scanned documents.
Now scroll trough all the pictures and move ‘white pictures with black lines on it’ to another folder. When this job is done, we OCR these files and import all the OCRed ‘white files’ by using the “Import OCRed Files” option within Intella. While importing, get a cup of coffee and give your eyes some rest
Analysing the pictures by viewing them is time consuming but it can be very valuable. We had a case in a foreign country. We used Intella and indexed a large pst-file. We did not have an OCR-tool on the laptop, but by using the thumbnail-view we discovered a whole bunch of very important scanned documents (jpg and pdf). Keyword searching is not always necessary to find your evidence.
Regards,
Hans