[mapserver-users] PHP MapScript pixel coordinates to map coordinates

[Daniel Degasperi]

Hi David,

have you already tried with this conversion:

$geo_x = $minx + (($pix_x / $map_width) * ($maxx- $minx));
$geo_y = $maxy - (($pix_y / $map_height) * ($maxy - $miny));

Daniel

Am 20.01.2010 04:57, schrieb Shorthouse, David:
> Folks,
>
> This question has no doubt been asked many times, but for the life of
> me I cannot find a solution. Here's what I'm trying to do:
>
> I have a jQuery-based front-end that uses the wonderful jcrop
> extension (http://deepliquid.com/content/Jcrop.html) that helps
> coordinate zoom. I'm hoping to use this same front-end to permit
> cropping of a resultant map image, which means I need to pass the four
> pixel corner coordinates, convert to map coordinates (projection may
> be variable), then set the extent such that the resultant map image
> will have the same dimensions as that described by the user on the
> front-end. So, how can I convert pixel coordinates to map coordinates?
> Note that the map projection is not always DD so I cannot merely use
> proportions as I have seen in some solutions. Surely this is easier
> than I am making it out to be.
>
> Thanks for any advice,
>
> David Shorthouse
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>    


-- 
   Daniel Degasperi
   Software Developer
   daniel.degasperi at r3-gis.com

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