[Mapserver-users] mapscript and float32 geotiffs
John Beisley - RSG
josb at pml.ac.uk
Thu Jun 10 10:59:54 EDT 2004
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Sean Gillies wrote:
> Hi John,
>
> The Python MapScript maintainer (me) and the GDAL guru (Frank)
> are both away from work at the users meeting. I don't have
> the resources to test, but I do see several things right away.
>
> Here is 4.2 code that should work. Note the differences
>
> # format name should be passed as an arg to factory
> new_format = mapscript.outputFormatObj('GDAL/GTiff', 'fgtiff')
> new_format.imagemode = mapscript.MS_IMAGEMODE_FLOAT32
>
> # Everything else is OK, no need to set mimetype or extension
>
> # Insert into map.
> your_map.appendOutputFormat(new_format)
>
> # Activate
> your_map.setImageType('fgtiff')
>
> I can't help but make a style suggestion -- mapscript.mapObj is
> a class. If you name instances of this class mapObj as well, you
> will eventually run into trouble right? Or maybe you are using
> the experimental next generation API with 'Map', 'Layer', etc, in
> which case carry on. :)
>
> Back to follow up on Monday.
> cheers,
> Sean
>
> --
> Sean Gillies
> sgillies at frii dot com
> http://users.frii.com/sgillies
>
Hi Sean,
Thanks for the prompt reply. Certainly your suggestion has helped me
tidy up that part of my code which I was never very happy with. However,
the segmentation fault remains. I have traced it to the msImageInitGD
function where it tries to execute the line:
tpixels = image->img.gd->tpixels[line];
The problem being is that image->img.gd->tpixels is NULL and hence
indexing it creates the segfault. I'm afraid that I don't know enough
about the internals of Mapserver to work out why it is zero in this case.
Regards,
- John
--
Website: www.pml.ac.uk
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Company No. 4178503
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Sean Gillies wrote:<br>
<blockquote cite="mid0EFB4769-BAE2-11D8-9095-000D9329D732 at frii.com"
type="cite">Hi John,
<br>
<br>
The Python MapScript maintainer (me) and the GDAL guru (Frank)
<br>
are both away from work at the users meeting. I don't have
<br>
the resources to test, but I do see several things right away.
<br>
<br>
Here is 4.2 code that should work. Note the differences
<br>
<br>
# format name should be passed as an arg to factory
<br>
new_format = mapscript.outputFormatObj('GDAL/GTiff', 'fgtiff')
<br>
new_format.imagemode = mapscript.MS_IMAGEMODE_FLOAT32
<br>
<br>
# Everything else is OK, no need to set mimetype or extension
<br>
<br>
# Insert into map.
<br>
your_map.appendOutputFormat(new_format)
<br>
<br>
# Activate
<br>
your_map.setImageType('fgtiff')
<br>
<br>
I can't help but make a style suggestion -- mapscript.mapObj is
<br>
a class. If you name instances of this class mapObj as well, you
<br>
will eventually run into trouble right? Or maybe you are using
<br>
the experimental next generation API with 'Map', 'Layer', etc, in
<br>
which case carry on. :)
<br>
<br>
Back to follow up on Monday.
<br>
cheers,
<br>
Sean
<br>
<br>
--
<br>
Sean Gillies
<br>
sgillies at frii dot com
<br>
<a class="moz-txt-link-freetext" href="http://users.frii.com/sgillies">http://users.frii.com/sgillies</a>
<br>
<br>
</blockquote>
<br>
Hi Sean,<br>
<br>
Thanks for the prompt reply. Certainly your suggestion has helped me
tidy up that part of my code which I was never very happy with.
However, the segmentation fault remains. I have traced it to the
msImageInitGD function where it tries to execute the line:<br>
<br>
<small><tt>tpixels = image->img.gd->tpixels[line];<br>
</tt></small><br>
The problem being is that <small><tt>image->img.gd->tpixels</tt>
<big>is NULL and hence indexing it creates the segfault. I'm afraid
that I don't know enough about the internals of Mapserver to work out
why it is zero in this case.<br>
<br>
Regards,<br>
<br>
- John<br>
<br>
</big></small>
<pre class="moz-signature" cols="72">--
Website: <a class="moz-txt-link-abbreviated" href="http://www.pml.ac.uk">www.pml.ac.uk</a>
Registered Charity No. 1091222
Company No. 4178503
-------------------------------------------------------------------
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in any way. Please notify the sender by replying to this e-mail or
e-mail <a class="moz-txt-link-abbreviated" href="mailto:forinfo at pml.ac.uk">forinfo at pml.ac.uk</a> and then delete the email without making
any copies or using it in any other way.
The content of this message may contain personal views which are
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