Zooming to match a raster scale

[Nick Dabner]

Thanks Bart,

So I take it that scale and mapxy are mutually exclusive with mapext?
Removing mapext always results in the error:

  msDrawMap(): Image handling error. Unable to initialize image.
  msCalculateScale(): General error message. Invalid image extent,
minx=-1.000000, miny=-1.000000, maxx=-1.000000, maxy=-1.000000

Any idea what I am doing wrong? Also I found out my scale is current
3.15 on the output map and needs to be 2.59, hence the poor output.
Would a resolution tag in the mapfile help?

ND

On 24/04/2005, at 10:45 PM, Bart van den Eijnden wrote:

> Hi Nick,
>
> you can probably use a combination of mapxy and scale.
>
> See Mapserver CGI reference:
> http://mapserver.gis.umn.edu/doc44/cgi-reference.html
>
> Best regards,
> Bart
>
> On Sun, 24 Apr 2005 22:38:34 +1000, Nick Dabner
> <dabner at OPTUSNET.COM.AU>
> wrote:
>
>> Hello list,
>>
>> I have a set of raster geotiffs tiled and working on mapserver 4.2 on
>> osx (thanks to william k).
>>
>> When viewing the rasters in mapserver, I find they suffer from some
>> slight scaling and never look anywhere near as good as the original
>> files. I have given dithering and PNG24 a go, but see that I probably
>> need to match my mapserver session's scale as close as possible to the
>> source data scale. Does this sound right?
>>
>> Using CGI mapserver, how can I specify an exact viewing area (to match
>> my calculations)? What argument would I choose.
>>
>> Attemping to pass IMGEXT=2482199.076569 4407814.492404 2484230.3854232
>> 4406291.0107634 just returns an extent error. Oh, I am in Melb Aust,
>> so
>> these are real coords.
>>
>> Any other ideas? The next step would probably be fixed zoom levels for
>> street, area, suburb, municipality and city or similar, with
>> preprocessed rasters for each level.
>>
>> regards,
>>
>> Nick
>>
>
>
>
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