Problem with reprojected images

[Frank Warmerdam]

Stephen Woodbridge wrote:
> Dirk Jesko wrote:
>> Ed,
>>
>> I already thought of something like this already. However, this should 
>> not happen. If the images are seamless (our images are seamless and do 
>> not have any borders) in the original projection, they should also be 
>> seamless after a reprojection. Otherwise, I would call it a bug.
> 
> May be, may be not! In a continuous math world this might be true, but 
> pixels are not continuous, this might be caused by a rounding or 
> numerical percision cause the pixel location to fall inside or outside 
> of the patch.
> 
>> I just tested an older version of Mapserver (4.6.1). That one creates 
>> seamless results, even if the images are reprojected. Only newer 
>> versions (tested 4.8.1) produce non-seamless images. Can someone 
>> confirm this?
> 
> Well a behavior change can certainly be considered a bug :) In which 
> case you might want to submit a simple test case (like two tiles and a 
> mapfile) the reproduct the results.

Folks,

I have to confess I haven't been following this discussion closely.  There
were fixes for 4.8.x intended to address cracking problems reported by a
user.  I can't recall the details but we can, if needed, dig back into the
history logs.

I would appreciate a submitted bug report with a *minimal* demonstration
of the problem.   My minimal, I mean a map file with two images in a tile
index and that I can just run "shp2img -m abc.map -o abc.png" to test.
Please ensure the bug report is assigned directly to me.

Once I reproduce the problem, I can try and analyse what is going wrong.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGF, http://osgeo.org