Orthophoto basics WAS: [Mapserver-users] Raster geotiff turns background yellow

[Frank Warmerdam]

Charlton Purvis wrote:
>> MAP
>    ...
> 
> IMAGETYPE jpeg
> 
> OUTPUTFORMAT
>   NAME jpeg
>   DRIVER "GD/JPEG"
>   MIMETYPE "image/jpeg"
>   IMAGEMODE RGBA
>   EXTENSION "jpg"
> END

Charlton,

As noted by others for GD 2.0.x you should get something at least 2.0.11 or
later.  Earlier versions have serious problems with alpha blending a few
other things.

I would also note that JPEG does not support IMAGEMODE RGBA only RGB.  I am
not sure what will happen if you get this wrong.  Likely nothing terrible,
just that the alpha is lost when writing out to the JPEG file, but it might
is possible it could cause other problems.

However, I am doubtful whether the GD version or the IMAGEMODE thing are
your problem if you are getting other layers OK with this OUTPUTFORMAT
configuration.

Have you tried this map with "shp2img" and with debugging all turned on?  Do
you get any messages?
eg.

shp2img -all_debug 1 -m my.map -o out.jpg

Best regards,

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