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<body class='hmmessage'><div dir='ltr'>Hi Jukka,<br><br><div>> To: gdal-dev@lists.osgeo.org<br>> From: jukka.rahkonen@mmmtike.fi<br>> Date: Fri, 21 Mar 2014 14:26:21 +0000<br>> Subject: Re: [gdal-dev] New compression library based on gdal design<br>> <br>> Aaron Boxer <boxerab <at> gmail.com> writes:<br>> <br>> > <br>> > Hello,<br>> > I recently started developing an open source jpeg2000 compression library<br>> using opencl.<br>> > I would like to base the library design on the very successful gdal<br>> library design.<br>> > Can anyone recomend any resources to help me to grok the high level design<br>> of gdal?<br>> > <br>> > Thanks so much,<br>> > Aaron<br>> <br>> Hi,<br>> <br>> I would like to see something that is open source and fast with JPEG2000. I<br>> think that it would be OK to support only a subset of JPEG2000 standard if<br>> the basic operations would be super fast. I took just a moment ago some<br>> timings for another purpose but they may be interesting. I converted the<br>> same 12000x12000 pixel image (432 MB uncompressed) with a few different methods:<br>> <br>> GDAL (64-bit) from tiff to tiff: 3 seconds<br>> GDAL (64-bit) ECWJP2 (SDK 5.0) from lossless JPEG2000 to tiff: 21 seconds<br>> GDAL (64-bit) JP2KAK (SDK 7.3.2) from lossless JPEG2000 to tiff: 14 seconds<br>> Kakadu 7.3.2 (64-bit) kdu_expand from lossless JPEG2000 to tiff: 7 seconds.<br>> <br>> The new library with opencl should be at least as fast as ECWJP2 with GDAL<br>> but the faster the better.<br>> <br>> It is interesting to see that native Kakadu application was two times faster<br>> than GDAL with JP2KAK driver of the same Kakadu version. Of course the use<br>> case is very simple.<br><br>Your test image was in fact 12000x12000x3 (=432 MB). That might explains why, maybe the GDAL driver is dealing with one band at the time, requesting to run the decompression 2 times more than the other application.<br><br>> <br>> -Jukka Rahkonen-<br>> <br>> _______________________________________________<br>> gdal-dev mailing list<br>> gdal-dev@lists.osgeo.org<br>> http://lists.osgeo.org/mailman/listinfo/gdal-dev<br></div> </div></body>
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