NDPI format and NDPITools

[Benjamin Gilbert]

On 10/01/2012 01:16 PM, Alvaro Gonzalez wrote:
> I've been invistigating around the mailing list for support on the NDPI
> format the Hamamatsu Nanozoomer throws. I've seen some work around it
> and, AFAIK, there's no support on Openslide, and, I think, no work
> currently going on (please correct me if I'm wrong).

The format is understood and small pieces of supporting code have been 
written, but so far that's it.

> We are using for that means NDPITools [1] , that's opensource (although
> I don't see any link providing source on their webpage), works mostly
> fine and it does even extract Z Levels.

Thanks for the link!  Looks like an interesting tool.

> Have any of you some contact with this proyect or their source so it
> could merge with Openslide, and/or any way of extracting metadata from
> NDPI files?

What we know about the NDPI metadata is recorded here:

http://openslide.org/formats/hamamatsu/#preliminary_ndpi_notes

You could use this information along with tiffdump or tiffinfo to 
extract at least some of the metadata.  The TIFF resolution information 
should be useful for MPP and the objective power appears to be stored in 
tag 65421.

Unfortunately, even if the NDPITools source is eventually released under 
GPLv3, we most likely won't be able to integrate it into OpenSlide for a 
couple reasons:

- Conflicting licenses: OpenSlide is LGPLv2.1.  NDPITools could take 
code from us, but not the other way around.

- NDPITools apparently uses modified versions of libtiff and libjpeg. 
This is a completely reasonable way to handle NDPI, but unfortunately it 
won't work for us: the policies of various Linux distributions (notably 
Fedora) prevent us from shipping modified versions of third-party 
libraries inside our own codebase.

--Benjamin Gilbert