Hi Adam and Steve, Thanks very much for the advice. The thing is, the shift I'm seeing is way more than 1/2 pixel on the edges. I'm off by quite a few degrees actually. I suspect it's as Julien thought earlier: I'm specifying an image size that is not consistent with the geographic extents. So I get back the number of pixels I've requested, but force a larger area than want. I guess what I'm looking for is WMS logic, but without having to make a WMS request.
Thanks again, Roger -- On Mon, Dec 8, 2008 at 5:20 PM, Adam Ryan <[EMAIL PROTECTED]> wrote: > Roger, > > I don't know if this would help, but I recently came across a similar > problem which was fixed by adding the processing directive to the > layer: > > PROCESSING "RESAMPLE=NEAREST" > > This fixed a problem when zooming in very close on a raster layer. > Apparently without this, mapserver changes the extent so that whole > source pixels are included and not split. > > More here... > > http://www.nabble.com/Raster-alignment-problem-td19900625.html > > Cheers, > > Adam > > On Mon, Dec 8, 2008 at 2:33 PM, Kralidis,Tom [Ontario] > <[EMAIL PROTECTED]> wrote: > > > > Roger: you can use MapScript WxS > http://mapserver.gis.umn.edu/docs/howto/wxs_mapscript as an approach to > run a WMS request via mapscript. Maybe that can work for you? > > > > ..Tom > > > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] on behalf of Roger André > > Sent: Mon 08-Dec-08 16:21 > > To: Julien-Samuel Lacroix > > Cc: mapserver-users@lists.osgeo.org > > Subject: Re: [mapserver-users] Difference in appearance between > "mode=map" andWMS > > > > 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 < > > [EMAIL PROTECTED]> 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 > >>> -- > >>> > >>> > >>> > ------------------------------------------------------------------------ > >>> > >>> _______________________________________________ > >>> mapserver-users mailing list > >>> mapserver-users@lists.osgeo.org > >>> http://lists.osgeo.org/mailman/listinfo/mapserver-users > >>> > >> > >> -- > >> Julien-Samuel Lacroix > >> Mapgears > >> http://www.mapgears.com/ > >> > > > > _______________________________________________ > > mapserver-users mailing list > > mapserver-users@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > > _______________________________________________ > mapserver-users mailing list > mapserver-users@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/mapserver-users >
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