Hi Adam and Steve,<br><br>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.<br>
<br>Thanks again,<br><br>Roger<br>--<br><br><br><div class="gmail_quote">On Mon, Dec 8, 2008 at 5:20 PM, Adam Ryan <span dir="ltr"><<a href="mailto:adamdryan@gmail.com">adamdryan@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Roger,<br>
<br>
I don't know if this would help, but I recently came across a similar<br>
problem which was fixed by adding the processing directive to the<br>
layer:<br>
<br>
PROCESSING "RESAMPLE=NEAREST"<br>
<br>
This fixed a problem when zooming in very close on a raster layer.<br>
Apparently without this, mapserver changes the extent so that whole<br>
source pixels are included and not split.<br>
<br>
More here...<br>
<br>
<a href="http://www.nabble.com/Raster-alignment-problem-td19900625.html" target="_blank">http://www.nabble.com/Raster-alignment-problem-td19900625.html</a><br>
<br>
Cheers,<br>
<font color="#888888"><br>
Adam<br>
</font><div class="Ih2E3d"><br>
On Mon, Dec 8, 2008 at 2:33 PM, Kralidis,Tom [Ontario]<br>
<<a href="mailto:Tom.Kralidis@ec.gc.ca">Tom.Kralidis@ec.gc.ca</a>> wrote:<br>
><br>
</div><div><div></div><div class="Wj3C7c">> Roger: you can use MapScript WxS <a href="http://mapserver.gis.umn.edu/docs/howto/wxs_mapscript" target="_blank">http://mapserver.gis.umn.edu/docs/howto/wxs_mapscript</a> as an approach to run a WMS request via mapscript. Maybe that can work for you?<br>
><br>
> ..Tom<br>
><br>
><br>
><br>
> -----Original Message-----<br>
> From: <a href="mailto:mapserver-users-bounces@lists.osgeo.org">mapserver-users-bounces@lists.osgeo.org</a> on behalf of Roger André<br>
> Sent: Mon 08-Dec-08 16:21<br>
> To: Julien-Samuel Lacroix<br>
> Cc: <a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
> Subject: Re: [mapserver-users] Difference in appearance between "mode=map" andWMS<br>
><br>
> Hi Julien,<br>
><br>
> That makes sense, but it doesn't work. I modified my mapfile so that I now<br>
> generate a 20_deg x 20_deg tile that is 600_pixels x 600_pixels. If I<br>
> georeference that image using the extents, I still get incorrect placement.<br>
> Maybe if I choose an output projection which always has square pixels, like<br>
> spherical mercator (?) this will work. I'll give it a shot.<br>
><br>
> Is there any way to give a WMS request via mapscript and NOT go through CGI?<br>
><br>
> Roger<br>
> --<br>
><br>
><br>
><br>
> On Mon, Dec 8, 2008 at 12:25 PM, Julien-Samuel Lacroix <<br>
> <a href="mailto:jlacroix@mapgears.com">jlacroix@mapgears.com</a>> wrote:<br>
><br>
>> Hi,<br>
>><br>
>> I guess would be that the WMS use non-square pixels. So if your BBOX x/y<br>
>> (rectangle in your case) doesn't match you WIDTH/HEIGHT ratio (square in<br>
>> your case) the map will appear stretched. MapServer will actually stretch<br>
>> the map to fit the extent in the WIDTH/HEIGHT.<br>
>><br>
>> The mode=map don't do that. If your extent doesn't have the same ratio, it<br>
>> adds some degree in your extent to fit the size.<br>
>><br>
>> Make sure your BBOX and EXTENT are a square in your requests and retry<br>
>><br>
>><br>
>> Julien<br>
>><br>
>> Roger André wrote:<br>
>><br>
>>> Hi All,<br>
>>><br>
>>> I think I'm having an instance of cranial flatulation, but maybe not.<br>
>>> Hopefully you can set me straight.<br>
>>><br>
>>> I need to create an image with Mapserver using mapscript that I can then<br>
>>> georeference manually and use in another application. It needs to look<br>
>>> exactly the same as the image I can already generate via a WMS call that<br>
>>> looks like this:<br>
>>><br>
>>> <a href="http://localhost/cgi-bin/mapserv?map=/var/www/mapfiles/hydro/hydro.map" target="_blank">http://localhost/cgi-bin/mapserv?map=/var/www/mapfiles/hydro/hydro.map</a><br>
>>> &SERVICE=WMS<br>
>>> &version=%221.1.1%22<br>
>>> &REQUEST=GetMap<br>
>>> &LAYERS=imagery<br>
>>> &STYLES=&BBOX=-125,39,-108,54<br>
>>> &WIDTH=600<br>
>>> &HEIGHT=600<br>
>>> &FORMAT=png<br>
>>> &SRS=epsg:4326<br>
>>><br>
>>> I'm testing my mapscript parameters using a simple "mode=map" call to<br>
>>> Mapserver, and the results I'm getting so far don't match the appearance of<br>
>>> the WMS output at all. My mapfile has the following extent and projection<br>
>>> info in it:<br>
>>><br>
>>> PROJECTION<br>
>>> "init=epsg:4326"<br>
>>> END<br>
>>><br>
>>> EXTENT -125.0 39.0 -108.0 54.0<br>
>>> SIZE 600 600<br>
>>><br>
>>> In addition to the mapfile projection specification, I am also specifying<br>
>>> the same projection info in each of my LAYERS as well.<br>
>>><br>
>>> Is it possible to do what I'm trying to accomplish here?<br>
>>><br>
>>> Thanks,<br>
>>><br>
>>> Roger<br>
>>> --<br>
>>><br>
>>><br>
>>> ------------------------------------------------------------------------<br>
>>><br>
>>> _______________________________________________<br>
>>> mapserver-users mailing list<br>
>>> <a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
>>> <a href="http://lists.osgeo.org/mailman/listinfo/mapserver-users" target="_blank">http://lists.osgeo.org/mailman/listinfo/mapserver-users</a><br>
>>><br>
>><br>
>> --<br>
>> Julien-Samuel Lacroix<br>
>> Mapgears<br>
>> <a href="http://www.mapgears.com/" target="_blank">http://www.mapgears.com/</a><br>
>><br>
><br>
> _______________________________________________<br>
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