[mapguide-trac] #743: PNG8 transparency is not working for GETDYNAMICMAPOVERLAYIMAGE

[MapGuide Open Source]

#743: PNG8 transparency is not working for GETDYNAMICMAPOVERLAYIMAGE
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   Reporter:  gingerbbm          |       Owner:       
       Type:  defect             |      Status:  new  
   Priority:  medium             |   Milestone:       
  Component:  Rendering Service  |     Version:  2.0.0
   Severity:  minor              |    Keywords:       
External_id:                     |  
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 I wanted to use PNG8 for the map tiling and overlay images, for its
 obvious advantages over PNG. However I discovered that it doesn't work
 correctly for overlay images.

 I edited ''serverconfig.ini'' and ''ajaxmappane.templ'' as follows:

 == \Server\Bin\serverconfig.ini ==
 {{{
 ImageFormat = PNG8
 }}}


 == \WebServerExtensions\www\viewerfiles\ajaxmappane.templ ==
 {{{
 function RequestMapImage(reqId)
 {
   url = webAgent +
 "?OPERATION=GETDYNAMICMAPOVERLAYIMAGE&FORMAT=PNG8&VERSION...
 }
 }}}

 The attached image ''png8_on_png8.png'' shows a polygon in the overlay
 image that ought to be translucent. Furthermore, there is no antialiasing
 on the edges of the polygon. Compare and contrast with the image
 ''png_on_png.png''.

 There has been some discussion about this topic here:[[BR]]
 [http://n2.nabble.com/PNG-PNG8-question-regarding-overlay-transparency-
 td1381702.html]

 The problem has been experienced on the following, running on Windows
 Server 2003 R2 Service Pack 2 and IIS V6.0:
  * MapGuide Open Source [2.0.0.2716 ]
  * MapGuide Enterprise 2009 [2.0.0.3202]

-- 
Ticket URL: <http://trac.osgeo.org/mapguide/ticket/743>
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