Thanks Andrea I will add them!
From: [email protected] [mailto:[email protected]] On Behalf Of Andrea
Aime
Sent: Monday, 13 February 2017 6:50 PM
To: Chris Jones <[email protected]>
Cc: [email protected]
Subject: Re: [Geoserver-users] ImageMosiac poor quality
On Mon, Feb 13, 2017 at 6:37 AM, Chris Jones
<[email protected]<mailto:[email protected]>>
wrote:
I haven’t created overviews or tiled the tiffs as I thought caching would
provide adequate performance.
Creating overviews is not just about performance, it's also about quality.
When creating overviews each level is computed as a summary of the previous
one, so each
pxiel in the overviews is a summary of all pixels of the original image.
When not creating them, the scaling algorithm does not go to read all original
pixels, it does
subsampling, reading 1 pixel every 1 to get closer to the requested resolution.
Trying to get
the same quality as with overviews would imply a massive overhead, reading all
pixels
and then doing repeated "scale by half" operations until reaching the desired
resolution.
So... add overviews.
Cheers
Andrea
--
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Ing. Andrea Aime
@geowolf
Technical Lead
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