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OMERO.web 5.1.0: Nearest neighbor when up-scaling possible?

PostPosted: Mon Apr 13, 2015 5:35 pm
by Sethur
Hi,

in OMERO.web 5.1.0 and prior versions, it appears that zoom factors of over 100% lead to some sort of interpolation between the pixels (probably bilinear or bicubic).

Although this kind of interpolation looks better, from a scientific point of view it would be great to also have the option of deactivating interpolation (aka nearest neighbor), because this makes the single pixel values much more obvious when zooming in and also reminds users of the resolution limits of their respective images. Bilinear interpolation can easily mislead users into seeing structures in the data where there are none.

As far as I know, most microscopy software provided by the vendors (LAS AF, Zen, Imspector, etc.) also purposely abstain from using interpolation when zooming in on images.

Cheers,

Tristan

Re: OMERO.web 5.1.0: Nearest neighbor when up-scaling possib

PostPosted: Tue Apr 14, 2015 8:26 am
by wmoore
Hi Tristan,

This is a feature that we support in Insight, but things are a bit more tricky in web.

I looked into this a while ago for OMERO.figure, but browsers tend to interpolate by default and are only experimentally allowing this to be disabled. See https://developer.mozilla.org/en-US/doc ... -rendering

I'll look at this again and see if this css support is good enough in modern browsers to use this in the web viewer.
The only other option is to use a canvas element to manually calculate the zoomed pixel values and display larger blocks of pixels, but this would obviously be a lot more work!

Regards,

Will.

Re: OMERO.web 5.1.0: Nearest neighbor when up-scaling possib

PostPosted: Tue Apr 14, 2015 8:30 am
by wmoore
Update: Just found this: http://phrogz.net/tmp/canvas_image_zoom.html which seems to do what we want.

Re: OMERO.web 5.1.0: Nearest neighbor when up-scaling possib

PostPosted: Tue Apr 14, 2015 9:04 am
by wmoore
I've created a ticket, but this is "Unscheduled" since the next releases are pretty full of other tickets currently.
http://trac.openmicroscopy.org/ome/ticket/12828

Here's a screenshot of what it looks like in Insight with "Interpolate" checkbox.