Mapserver 44 image display problem

[Sean Gillies]

On Dec 15, 2004, at 7:17 AM, Mark Adams wrote:

> Well, I did the same and it worked - I now get the image in colour. But
> surely this isn't the way it's supposed to work? One immediate problem
> that arises is that none of the map file elements that exist at the
> CLASS level can now be used with raster layers, including the keyimage
> element I had been using.
>
> Should I file a bug for this?
>
> Also, I still have the problem with transparency on the GIF I'm using
> for the north arrow. On both machines that I'm using mapserver 44 on,
> this image shows with an opaque grey colour background, which should be
> transparent. I tried setting TRANSPAREMT ON in the map file, now
> anything white becomes this grey colour - legend image background, map
> window background etc. Is this a GD issue?
>
> Thanks for your help.
>
> ------------------------------
> Mark Adams
> Business & Systems Analyst
> Cuesta Systems Inc.
> 5230 South Service Road
> Burlington, ON L7L 5K2
> Phone: 905-333-4544 x14
> Fax: 905-333-0455
> Email: markadams at cuestasys.com
>
>
> -----Original Message-----
> From: Sean Gillies [mailto:sgillies at frii.com]
> Sent: Tuesday, December 14, 2004 12:06 PM
> To: Mark Adams
> Cc: MAPSERVER-USERS at LISTS.UMN.EDU
> Subject: Re: Mapserver 44 image display problem
>
> On Dec 14, 2004, at 9:31 AM, Mark Adams wrote:
>
>> We're working with the binary download of Mapserver 44 and mapscript
>> from
>> the Maptools site. We have everything working OK, however our colour
>> raster
>> image is displaying as greyscale, and our north arrow GIF is showing
>> without transparency. We've noticed this problem on 2 different
>> machines
>> we've tried so far. Any ideas what might be causing this problem?
>>
>> Thanks in advance,
>>
>> Mark Adams
>> markadams at cuestasys.com
>>
>>
>
> Mark,
>
> I ran into a problem with the same symptoms today.  I had been
> assigning an default class and style to the raster layer.  Once
> I fixed this, full RGB output was restored.
>
> cheers,
> Sean
>

Try class without a style and no mapserver 3-ish color definitions
in the class.  If that doesn't work, file a bug.

Overlaying a transparent symbol on a RGB map, if it ever worked,
was definitely broken in MapServer 4.0.  I fixed it in 4.2.4 and
4.4, but now you need to explicitly direct MapServer with a

    TRANSPARENCY ALPHA

for layers that use transparent pixmaps.  In the most recent
versions, you can even use alpha transparent PNG symbols.  The
new keyword exists because this is a fairly expensive operation
and need not be done for most layers.

The new directive is *not* needed when drawing indexed transparent
pixmaps like your GIF onto 256-color output.  That should work as
before.

Finally, map-level transparency is deprecated.  You should adjust
this within an OUTPUTFORMAT block.  It has no meaning for RGB
output anyway.

cheers,
Sean


--
Sean Gillies
sgillies at frii dot com
http://users.frii.com/sgillies