I need the ability to be able to display ECW and JPEG2000 format files within MapServer via a Community Mapbuilder client which sends WMS requests for the images to MapServer

[Frank Warmerdam]

John Mitchell wrote:
> Hi Frank,
> 
> I now able to display ECW type files via mapserver within a community 
> mapbuilder web browser client.  I had question on part of the sample map 
> file that you sent:
> OUTPUTFORMAT
>  NAME jpeg2000
>  DRIVER "GDAL/JP2ECW"
>  MIMETYPE "image/jpeg2000"
>  FORMATOPTION "TARGET=95"
>  IMAGEMODE RGB
> END
> 
> What does TARGET=95 mean?

John,

This means that I am requesting 95% reduction in image size during
compression - ie. 20:1 compression.

> I am having good success (as far as image quality and small size 
> downloaded to the browser) with displaying my image data as jpeg within 
> community mapbuilder as an example
>       <FormatList>
>         <Format current="1">image/jpeg</Format>
>       </FormatList>
> But when I try displaying it as a png as an example.  I get poor quality 
> as far as the color.
>       <FormatList>
>         <Format current="1">image/png</Format>
>       </FormatList>

You like want PNG24 format.  The plain PNG format results in a reduction
to 8bit which causes a lot of damage to the image.  The predefined 24bit
PNG output format is called "PNG24", and has a mimetype of
"image/png; mode=24bit"

> What application do you use to create your .ECW files?

The original ecw file I was serving from was one I downloaded from
geotorrent.org.  But I do sometimes use gdal_translate to produce
ecw files.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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