Resolution information for various formats

[Benjamin Gilbert]

On 07/12/2012 06:58 AM, Yves Sucaet wrote:
> We're trying to embed a scalebar on top of various image type. We've
> been successfull to do this for MRXS files by using the
> MICROMETER_PER_PIXEL_X and the XResolution tag for some TIFF based images.
> We are having trouble though with the resolution unit for some TIFF
> images such as Aperio. Some either state inches as the resolution unit
> and others have no X and Y resolution fields - Aperio for example.
> Does OpenSlide have any resolution information for the various supported
> formats?

See this bug:

https://github.com/openslide/openslide/issues/19

and this list:

http://openslide.org/Requested%20Properties/

I think we should start exposing standard properties for this 
information, even though the values in the slide file may not be 
entirely accurate.  Your code shouldn't have to understand 
vendor-specific properties to get at common metadata.

--Benjamin Gilbert