AW: [Mapserver-users] Mapserver printing

[Lowell Filak]

Your note on a 0-size PNG is very interesting.
In our case we actually create images with a specific name so images that may be requested more than once are "cached" and not recreated a second time for 24 hours.
Each time we see an instance where the file seems to only partially load into the browser a reload (of the exact same file) works fine.
I don't recall ever seeing a 0-size file (out of MapServer anyways).?
Lowell F.

The following message was sent by "Arnulf Christl \(CCGIS\)" <arnulf.christl@ccgis.de> on Wed, 28 May 2003 10:57:27 +0200.

> Hi,
> we have approached the problem in a little different way. Our WMS client has
> to be able to query all sorts of severs and many have a farily low max limit
> for the image size they will produce (MapServer is a positive exception to
> that rule). Therfore the client breakes down the required large map into
> several smaller tiles which the corresponding server is able to deliver. The
> resulting tiles are then put back together in a simple HTML page. This is a
> tedious process, if you want to be able to use several different services,
> but maybe you can use this idea to reduce the size of individual images.
> When we request very large tiled maps sometimes we also have noticed the
> effect that one tile is blank (the file exists but has no content). As this
> happens with different servers I guess that it has to do with PNG and not
> with the server.
> 
> Regards, Arnulf.
> 
> -----Ursprüngliche Nachricht-----
> Von: mapserver-users-admin@lists.gis.umn.edu
> [mailto:mapserver-users-admin@lists.gis.umn.edu]Im Auftrag von Lowell
> Filak
> Gesendet: Dienstag, 27. Mai 2003 22:10
> An: Zamil Murji; mapserver-users@lists.gis.umn.edu
> Betreff: Re: [Mapserver-users] Mapserver printing
> 
> 
> I'm not so sure that there is a limit.
> I have found that PNG works extremely well for large images and I've never
> had a problem with generating larger than 8.5x11 images w/ MapServer.
> I just finished working with one that is 10218x8814 (~34x30) (no it wasn't
> created with mapserver, but then that is why I am not sure there is a
> limit).
> Okay, I had to check it out... & MapServer reliably created a 6100x6100
> (34x34@180dpi - which appears to be the max res. for that size that we can
> pump through ZehRaster to our plotter) PNG file (the browser wouldn't render
> it but Gimp opened it fine).
> As far as the blank PNG in the browser is concerned:
> What we have seen is that sometimes only part of the PNG is loaded, but that
> only seems to happen on one of the apps we have that tracks vehicles and
> loads a new map every 10-120 seconds.
> We have not tracked down why it happens but it would seem that the html is
> finished and loaded by the browser with the "img src" specified before the
> image file is actually finished.
> Lowell F.
> 
> The following message was sent by "Zamil Murji" <Zamil.Murji@divestco.com>
> on Fri, 23 May 2003 11:16:03 -0600.
> 
> > Hi,
> >
> > We are currently trying to use mapserver to print images on an 8.5x11 inch
> paper using the web. Up to date we have been very successfull. However, we
> are now trying the next step - PLOTTING. I was wondering if anyone has any
> idea how to approach this issue. I read in the past that mapserver has a
> limit to the size of image that can be created, if so, how do I get around
> this. Any suggestions would be welcome.
> >
> > Also, I noticed that when we started using png images all over our site.
> Sometimes they would come back empty. NO error messages from mapserver, just
> an empty image. If you refreshed the screen everything would start working
> again. The image would be displayed again. Anybody observe similar output?
> Once again, it happens randomly. Sometimes it works and sometimes it
> doesn't.
> >
> > Zamil
> >
> > _______________________________________________
> > Mapserver-users mailing list
> > Mapserver-users@lists.gis.umn.edu
> > http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> 
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users@lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> 
> 
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users@lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users

_______________________________________________
Mapserver-users mailing list
Mapserver-users@lists.gis.umn.edu
http://lists.gis.umn.edu/mailman/listinfo/mapserver-users