[FWTools] gdal JPEG2000 driver and shp2img , MapServer

karsten vennemann karsten at terragis.net
Fri Feb 18 00:42:44 EST 2011


Thanks Frank,

> I'm not sure why the FWTools MapServer is not finding the 
> JP2ECW driver if you have it with gdalinfo.  However, your 
> project isn't going to work the way you want anyway.  There 
> is no way to assemble a single map in memory to large that it 
> will be 500MB when jpeg2000 compressed.  You are going to 
> need to come up with a scheme to produce the final result in 
> chunks with MapServer and then assemble them into a final 
> product as a post processing step.

Ok I was not aware that all of this is happening in memory ;) with JPEG2000 format... I could script the creation of tiles via MapServer and assemble the result later yes... but
 
> Note that the JP2ECW driver only supports writing large 
> JPEG2000 files if you set the LARGE_OK creation option on, 
> and you are required to have a valid license to do so.  So I 
> also don't think you ought to be using the JP2ECW driver to 
> assemble your final jpeg2000 product.

... then this fact does not really leave that as an option... 

..there seems to be not really many (any?) formats or libraries that freely support creation of huge images / compression of images I guess . Or are there any other good OS alternatives to create compressed imagery ?

One option would be to convince my client ot accept a collection of tiles as tiff e.g. which would be a better way to do this anyway ...
Cheers
Karsten



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