[Mapserver-users] Raster: rotation params in WLD file

[Lars V. Nielsen]

Hi Frank,

Indeed it doesn't, it simply ignores the secondar parameters completely (I have tried).

> ..., but if you handle a raster through GDAL in MapServer then it
> can be rotated properly to display in MapServer.

Does this mean that I can use e.g. the below output format spec in 3.7 to display rotated raster images ?

OUTPUTFORMAT
 NAME jpeg_gdal
 MIMETYPE "image/jpeg"
 DRIVER "GDAL/JPEG"
 IMAGEMODE RGB
 FORMATOPTION "QUALITY=80"
 TRANSPARENT OFF
END


Best regards/Med venlig hilsen
Lars V. Nielsen
GisPro, Denmark
http://www.gispro.dk/
http://hjem.get2net.dk/lars-online/
WGS84: 10.20'40"E 55.20'20"N
----- Original Message ----- 
From: "Frank Warmerdam" <warmerdam at pobox.com>
To: "Marian Grigoras" <mgrig at mnet-online.de>; "UMN MapServer" <mapserver-users at lists.gis.umn.edu>
Sent: Saturday, February 22, 2003 7:01 PM
Subject: Re: [Mapserver-users] Raster: rotation params in WLD file


> Marian Grigoras wrote:
> > Hello,
> >  
> > Could someone please clarify what the 2nd and the 3rd paratemers in a 
> > .WLD file mean?
> > All that I could find on the topic is that they are normally 0.00 :-)) 
> > and that is not very
> > encouraging if I want to define some raster maps that are not 
> > North-oriented.
> > I tried to play with the parameters blindly, but I did not notice any 
> > change in the output
> > image, whatever I write on these 2 lines. Are these parameters supported 
> > at all?
> 
> Marian,
> 
> They are rotational coefficients.
> 
> If W[i] is one of lines 0 through 5 of the world file you can calculate
> the georeferenced location of pixel [Xr,Yr] as:
> 
>   Xgeo = W[4] + W[0] * Xr + W[2] * Yr
>   Ygeo = W[5] + W[4] * Xr + W[3] * Yr
> 
> Most of the worldfile handling in mapserver ignores the rotational
> coefficients, but if you handle a raster through GDAL in MapServer then it
> can be rotated properly to display in MapServer.
> 
> Note that MapServer does not support producing rotated map results.  They
> are always north up.
> 
> Best regards,
> 
> 
> -- 
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
> 
> 
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