[mapguide-internals] RE: changing mapguide's image type

[Trevor Wekel]

Hi Andy,

The PNG/JPG paramter will be added for tiles in RFC 13.  Adding a global
configuration parameter for the overlay is problematic for the reasons
you give below.  The overlay has to be PNG if you want transparency but
PNG is an expensive format for raster imagery.  For raster imagery on a
base map, a JPG tile with PNG overlay should be more effective.  This
will be supported by RFC 13.

Thanks,
Trevor

-----Original Message-----
From: mapguide-internals-bounces at lists.osgeo.org
[mailto:mapguide-internals-bounces at lists.osgeo.org] On Behalf Of Andy
Morsell
Sent: Monday, March 05, 2007 10:13 AM
To: mapguide-internals at lists.osgeo.org
Subject: [mapguide-internals] RE: changing mapguide's image type


Trevor,
Are you going to be adding this configuration parameter in RFC 13?  I
would also like to see this be a user config parameter for normal AJAX
viewer map renderings.  This would probably be outside the context of
this RFC, however.  In the sites that I have manually changed this
setting in ajaxmappane.templ, the performance increase has been
profound.  I'm afraid that the default format of PNG, while visually
nicer, is causing many sites to appear much slower than they could be if
using JPG.  This is mostly apparent in cases where the map has imagery
layers and PNG transparency has no advantage.  For instance, a site I
just made this switch to, Kids GIS, a standard AJAX map request resulted
in a map image of about 1 MB in size whereas changing it to JPG results
in about 75 KB images.  This has greatly improved the client experience
- but again, does not look quite as nice.

Ideally this parameter would be configurable on a web layout by web
layout basis and not be global site parameter, as it is now.

Thanks for considering this.

Andy



Trevor Wekel wrote:
> 
> Hi Paul,
> 
> Not currently.  It's a hardcoded parameter.  I may be able to add this

> to RFC 13 but it would be a global parameter for the Site Server.  
> Would you also want control over the JPG compressibility?
> 
> Thanks,
> Trevor
> 
> -----Original Message-----
> From: mapguide-internals-bounces at lists.osgeo.org
> [mailto:mapguide-internals-bounces at lists.osgeo.org] On Behalf Of Paul 
> Spencer (External)
> Sent: Monday, February 05, 2007 10:25 AM
> To: MapGuide Internals Mail List
> Subject: [mapguide-internals] changing mapguide's image type
> 
> Hi,
> 
> is it possible to change the image type used by mapguide from PNG to 
> JPG?  I thought I saw this option in the system administration tool at

> one point but now I can't find it.
> 
> Also, is it possible to use different image types?  I have a client 
> who wants to use tiles and cache imagery as jpg because png is too 
> big, but png is better for the rest of the app.
> 
> Cheers
> 
> Paul
> 
> +-----------------------------------------------------------------+
> |Paul Spencer                          pspencer at dmsolutions.ca    |
> +-----------------------------------------------------------------+
> |Chief Technology Officer                                         |
> |DM Solutions Group Inc                http://www.dmsolutions.ca/ |
> +-----------------------------------------------------------------+
> 
> 
> 
> 
> _______________________________________________
> mapguide-internals mailing list
> mapguide-internals at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapguide-internals
> 
> _______________________________________________
> mapguide-internals mailing list
> mapguide-internals at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapguide-internals
> 
> 

--
View this message in context:
http://www.nabble.com/changing-mapguide%27s-image-type-tf3175664s16610.h
tml#a9315847
Sent from the MapGuide Internals mailing list archive at Nabble.com.

_______________________________________________
mapguide-internals mailing list
mapguide-internals at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapguide-internals