[mapserver-users] Issues with Bilinear Rendering of Raster Images in MapServer 6.0.0-2

[Frank Warmerdam]

On 11-05-19 12:42 PM, vanwars wrote:
> Hello,
>
> I just upgraded MapServer today on (Ubuntu Lucid Lynx) to 6.0.0-2 from
> MapServer 5.6.6, and am experiencing a weird error with the bilinear
> rendering from GeoTiff (the underlying data store) to PNG (the display
> format).  Whereas before there were nice tapered edges and smoothing, there
> is now a strange black / blue /green border around all of our pngs.  I read
> through the upgrade documentation, and it seems like there have been a
> number of changes to the way in which rasters are rendered, but I can't
> figure out the element(s) that I might be able to adjust to get the rasters
> to look fabulous again.  Has anyone run into this particular issue?  I've
> attached before / after pngs.
>
> Thank you!
>
> Sarah
>
> Relevant parts of my map config file
> http://osgeo-org.1803224.n2.nabble.com/file/n6382806/MapServer5.6BilinearInterpolation.png
> MapServer5.6BilinearInterpolation.png
> http://osgeo-org.1803224.n2.nabble.com/file/n6382806/MapServer6.0BilinearInterpolation.png
> MapServer6.0BilinearInterpolation.png :

Sarah,

My take would be that previously the nodata value of the raster was
being recognised, and was not getting blended with real values but now
that is not the case.  There have been some advances in this area though
now it is looking like a regression in your case.  I would appreciate it
if you could prepare a ticket with sufficient detail for me to reproduce
the problem.  Ideally a pointer to the dataset, your mapfile and a
"shp2img" command demonstrating the problem.

Make sure to have it assigned to "warmerdam" or to email me after the ticket
is created.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent