[mapserver-users] Difference in appearance between "mode=map" and WMS

[Julien-Samuel Lacroix]

Hi,

Did you try the other way around? Making the WMS request with a square BBOX?

Mapserver should return a valid image. Maybe others may help, I remember 
a bug of a 1 pixel error in some cases, but I don't remember what it was 
exactly.

Julien

Roger André wrote:
> Hi Julien,
> 
> That makes sense, but it doesn't work.  I modified my mapfile so that I 
> now generate a 20_deg x 20_deg tile that is 600_pixels x 600_pixels.  If 
> I georeference that image using the extents, I still get incorrect 
> placement.  Maybe if I choose an output projection which always has 
> square pixels, like spherical mercator (?) this will work.  I'll give it 
> a shot.
> 
> Is there any way to give a WMS request via mapscript and NOT go through CGI?
> 
> Roger
> --
> 
> 
> 
> On Mon, Dec 8, 2008 at 12:25 PM, Julien-Samuel Lacroix 
> <jlacroix at mapgears.com <mailto:jlacroix at mapgears.com>> wrote:
> 
>     Hi,
> 
>     I guess would be that the WMS use non-square pixels. So if your BBOX
>     x/y  (rectangle in your case) doesn't match you WIDTH/HEIGHT ratio
>     (square in your case) the map will appear stretched. MapServer will
>     actually stretch the map to fit the extent in the WIDTH/HEIGHT.
> 
>     The mode=map don't do that. If your extent doesn't have the same
>     ratio, it adds some degree in your extent to fit the size.
> 
>     Make sure your BBOX and EXTENT are a square in your requests and retry
> 
> 
>     Julien
> 
>     Roger André wrote:
> 
>         Hi All,
> 
>         I think I'm having an instance of cranial flatulation, but maybe
>         not.  Hopefully you can set me straight.
> 
>         I need to create an image with Mapserver using mapscript that I
>         can then georeference manually and use in another application.
>          It needs to look exactly the same as the image I can already
>         generate via a WMS call that looks like this:
> 
>         http://localhost/cgi-bin/mapserv?map=/var/www/mapfiles/hydro/hydro.map
>         &SERVICE=WMS
>         &version=%221.1.1%22
>         &REQUEST=GetMap
>         &LAYERS=imagery
>         &STYLES=&BBOX=-125,39,-108,54
>         &WIDTH=600
>         &HEIGHT=600
>         &FORMAT=png
>         &SRS=epsg:4326
> 
>         I'm testing my mapscript parameters using a simple "mode=map"
>         call to Mapserver, and the results I'm getting so far don't
>         match the appearance of the WMS output at all.  My mapfile has
>         the following extent and projection info in it:
> 
>          PROJECTION
>            "init=epsg:4326"
>          END
> 
>          EXTENT -125.0  39.0 -108.0  54.0
>          SIZE 600 600
> 
>         In addition to the mapfile projection specification, I am also
>         specifying the same projection info in each of my LAYERS as well.
> 
>         Is it possible to do what I'm trying to accomplish here?
> 
>         Thanks,
> 
>         Roger
>         --
> 
> 
>         ------------------------------------------------------------------------
> 
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> 
> 
>     -- 
>     Julien-Samuel Lacroix
>     Mapgears
>     http://www.mapgears.com/
> 
> 

-- 
Julien-Samuel Lacroix
Mapgears
http://www.mapgears.com/