[Mapserver-users] cascading transparently from ArcIMS

[bartvde at xs4all.nl]

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.