MPP question

[j.hudecek at nki.nl]

Thanks! I'm not sure how I missed it the parameter is even called pixelsPerMeter...

-----Original Message-----
From: Benjamin Gilbert [mailto:bgilbert at cs.cmu.edu] 
Sent: vrijdag 19 augustus 2016 5:24
To: openslide-users at lists.andrew.cmu.edu
Cc: Jan Hudecek
Subject: Re: MPP question

On Thu, Aug 18, 2016 at 03:40:59PM +0000, j.hudecek--- via openslide-users wrote:
> I'm using openseadragon with scalebar plugin to display digital 
> pathology slides from a Hamamatsu scanner with a scale bar.  I've 
> converted them from .ndpi files with VIPS (which uses OpenSlide I 
> believe).  How should I initialize the mpp (microns per pixel) in 
> OpenSeaDragon using the openslide.mpp-x from the vips-properties.xml?  
> I tried multiplying the number (0.2271) by 1 million (seemed like a 
> good guess) but I'm still off by a factor of 20 or so.

Hi Jan,

OpenSeadragonScalebar expects pixels per meter, so the correct calculation is (1e6 / MPP).

--Benjamin Gilbert