[Mapserver-users] cascading transparently from ArcIMS

[Daniel Morissette]

bartvde at xs4all.nl wrote:
> Hi list,
> 
> has anybody succeeded in getting Mapserver to display images from ArcIMS
> in a transparent way?
> 
> I tried using PNG (both 8 and 24 bit) on ArcIMS 4.0, since I do not have a
> GIF license for it. But I cannot get it to display transparently.
> 
> Any info would be appreciated.
> 
> Best regards,
> Bart
> 
> In the WMS client HWOTO it says:
> 
> PNG format with transparent=true does not work well with all servers. For
> instance some servers use the alpha channel for transparency (RGBA images)
> but this is not well supported by MapServer at the moment. So you may be
> forced to request GIF format maps in those cases. Transparent PNGs
> produced by the MapServer WMS work well though since they are paletted
> images.


I believe we've used transparent ArcIMS layers as part of WMS client 
maps before and I also thought most of those PNG issues had been 
resolved in 4.0, making this note obsolete, but I could be wrong with 
both affirmations.  If you have a mapfile pointing to public ArcIMS 
layers that reproduces this then perhaps you could file a bug and we can 
try to have a look.

Daniel
-- 
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  Daniel Morissette               morissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
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