[mapserver-dev] Fwd: Considering a new WMS/WMTS output format: jpeg or png (JPENG for friends)

[Jeff McKenna]

Forwarding interesting idea on the GeoServer-devel list.  Seems like 
something that would interest MapServer-ers serving through WMS as well. 
-jeff



-------- Forwarded Message --------
Subject: 	[Geoserver-devel] Considering a new WMS/WMTS output format: 
jpeg or png (JPENG for friends)
Date: 	Tue, 7 Jun 2016 18:50:02 +0200
From: 	Andrea Aime <andrea.aime at geo-solutions.it>
To: 	Geoserver-devel <geoserver-devel at lists.sourceforge.net>



Hi all,
when working with imagery it happens often enough that one wants the 
compression
factor of a JPEG, but also transparency at the raster data edges.
Unfortunately one cannot have both... or can she?

With tiled maps we can introduce a new output format, which I nicknamed 
JPENG
(JPEg or pNG) that would return the right compression depending on the 
tile content:
if it's fully opaque, JPEG, if there is any transparency, PNG instead, 
of course setting
the right return type headers so that the browser can do the right decoding.

It's simple enough and would save significant bandwidth (and also CPU, 
JPEG is
faster to compress) for imagery that also needs occasional transparency 
support.

I'd add this at a WMS output format, and if time allows, WMTS too... but 
no guarantees,
I have actually no funding backing any of this (I'm doing it for another 
system), but it seems
quick to implement in GeoServer  too and would be a pity to lose it.

Objections? Suggestions for a better name (I checked a few other 
variants, but they seem to be
already in use on the internet with a different meaning)?

Cheers
Andrea