[Mapguide-trac] [mapguide-trac] #743: AGG Renderer does not properly handle transparency for non-PNG image formats

[MapGuide Open Source]

#743: AGG Renderer does not properly handle transparency for non-PNG image
formats
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   Reporter:  gingerbbm          |       Owner:       
       Type:  defect             |      Status:  new  
   Priority:  medium             |   Milestone:  2.4  
  Component:  Rendering Service  |     Version:  2.2.0
   Severity:  major              |    Keywords:       
External_id:                     |  
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Comment(by bscott):

 I just worked around this problem.
 the problem is not only related to the transparency but the image quality
 in a whole.
 GD does handle png8 very well ( neither png24 with transparency :) )

 I have took some piece of code from Mapserver to fix the problem.
 For my point of view the png8 output is very great. With Sheboygan i dont
 see any difference between png24 and png8 except for the size of the image
 ( 3 to 4 time smaller)

 Fix is done on MgDev/Common/Renderers/AGGImageIO.cpp
 plus a new file mapquantization.cpp ( from mapserver )

 Give it a try, i worth the effort
 Just switch PNG to PNG8 in the ajaxmappane.templ

 And therefore there is no reason to keep the selection image in PNG it
 always should be PNG8

 Patch is attached: high_quality_png8.patch

 Bruno Scott
 Geomap

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Ticket URL: <http://trac.osgeo.org/mapguide/ticket/743#comment:15>
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