[mapserver-users] Clasify 16 bits Geotiff

[Frank Warmerdam]

 Inés,

I see that you have two classes for values greater and less than
100.  This is fine, but if you set processing directive for scale
to -10 to 10 then the classifier is unable to distinguish between
values that are greater than 100 and less than 100. That is because
the scaling is done before the classification.  So if you want to
control the scaling it should be based on what you need for
the classification.

If all you need to do is differentiate between <100 and >100
you could just use SCALE=-900,1100 and set NUM_BUCKETS to
some small even number.

Best regards,

On Thu, Mar 18, 2010 at 8:55 AM, Inés García <igtrujillo78 at gmail.com> wrote:
> Hello,
>
> I need to clasity a 16 bits raster Geotiff. I am ussing the PROCESSING
> directive (PROCESSING "SCALE=-10,10") but it does not work.
>
> Can MapServer classify that kind of raster file?

>  CLASS
>    NAME "< 100"
>     EXPRESSION ('[pixel]' < '100')
>     STYLE
>       COLOR 193 247 178
>     END
>   END
> CLASS
>    NAME ">100"
>     EXPRESSION ('[pixel]' >= '100')
>     STYLE
>       COLOR 210 232 137
>     END
>  END


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