mapserver error

[Ed McNierney]

Christopher -

Thanks; it was not obvious to me that the second problem was also seen in the OpenLayers application.  The image on the OpenLayers discussion seems to indicate a MapServer crash or other failure, as you've already suggested there.

Lee, I think you should ignore the "blurry" problem for now and focus exclusively on:

" I take the URL that is requesting the information from mapserver, then I get: "The specified CGI application misbehaved by not returning a complete set of HTTP headers." "

You seem to be building on quicksand, and if you don't fix the foundation there's no point in trying to figure out why the pictures on the walls don't hang straight.

If you can post details about the URL and the error we might be able to try to help debug.  Looking for debug and Web server logs can also be helpful to understand why the CGI failed, as is running mapserv from the command line.

	- Ed

Ed McNierney
Chief Mapmaker
Demand Media / TopoZone.com
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396

-----Original Message-----
From: Christopher Schmidt [mailto:crschmidt at metacarta.com] 
Sent: Wednesday, January 16, 2008 1:18 PM
To: Ed McNierney
Cc: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] mapserver error

On Wed, Jan 16, 2008 at 01:13:33PM -0500, Ed McNierney wrote:
> Lee -
> 
> INTERLACE=ON is not "wrong".  Tim is pointing out that if you're viewing an interlaced output image, the first, alternating set of scanlines will be displayed and then your browser will start again at the top of the image, filling in the alternate interlacing lines.  This will cause the top of the image to appear complete while the bottom is "blurry".  You can see variations on these visual artifacts depending on your browser, and the effect is more pronounced over a slow connection.
> 
> But if the image still looks blurry at the bottom even after you're certain the image has been completely loaded, then this is not your problem.

Note that this will almost never be the case with OpenLayers because
OpenLayers hides images until they are completely loaded (for technical
reasons unrelated to this), so if someone reports this behavior in
OpenLayers, you can usually be sure it's not an interlacing thing.

> It's hard to diagnose visual problems in text; can you either post the output image or (preferably) a public URL where the image can be viewed?

There is a 'bmp' attached to
http://openlayers.org/pipermail/users/2008-January/004506.html which
might be the one.

Regards,
-- 
Christopher Schmidt
MetaCarta