[gdal-dev] Tilesize in JPEG2000 and gdalinfo

[Rahkonen Jukka (MML)]

Thanks, Even.

This information may be less interesting once we have a released OpenJPEG driver that can handle big tiles properly.
The reason for my question was this error message that I got from my colleague who is cutting excerpts from a big VRT


Input file size is 1332094, 2304162

0...10...20...30...ERROR 1: Cannot decode tile, memory error



ERROR 1: opj_decode() failed

ERROR 1:

/vsicurl/http://kartat.kapsi.fi/files/orto/etrs-tm35fin/mara_v_25000_50/2013/N53/02m/1/N5144H.jp2,

band 1: IReadBlock failed at X offset 0, Y offset 0: opj_decode() failed

My guess is that error is due to this single tiled image.  Most JPEG2000 images in the VRT are written with tilesize 1024x1024.

-Jukka-


Lähettäjä: Even Rouault [mailto:even.rouault at spatialys.com]
Lähetetty: 5. syyskuuta 2017 12:09
Vastaanottaja: gdal-dev at lists.osgeo.org
Kopio: Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi>
Aihe: Re: [gdal-dev] Tilesize in JPEG2000 and gdalinfo


Hi Jukka,



>

> If I run gdalinfo against the JPEG2000 image in

> http://kartat.kapsi.fi/files/orto/etrs-tm35fin/mara_v_25000_50/2013/N53/02m

> /1/N5144H.jp2 the JP2ECW driver reports the blocksize as (256x256) and

> JPEG2000OpenJPEG driver reports that the block size is (1024x1024).



Yes for single tiled images, all JPEG2000 drivers will report a block size

of much smaller dimension to avoid GDAL consuming too much memory.



>

> What interests me would be to know the fact that this image has only one

> JPEG2000 tile with a tilesize of (11754x11754). Is there any

> driver-independent way for getting this information?



You can use the opj_dump utility from openjpeg, or a GDAL Python script

https://svn.osgeo.org/gdal/trunk/gdal/swig/python/samples/dump_jp2.py



$ python swig/python/samples/dump_jp2.py /vsicurl/http://kartat.kapsi.fi/files/orto/etrs-tm35fin/mara_v_25000_50/2013/N53/02m/1/N5144H.jp2 | grep "siz\""



<Field name="Rsiz" type="uint16" description="Unrestricted profile">0</Field>

<Field name="Xsiz" type="uint32">11754</Field> <-- image width

<Field name="Ysiz" type="uint32">11754</Field> <-- image height

<Field name="XOsiz" type="uint32">0</Field>

<Field name="YOsiz" type="uint32">0</Field>

<Field name="XTsiz" type="uint32">11754</Field> <-- tile width

<Field name="YTsiz" type="uint32">11754</Field> <-- tile height

<Field name="Csiz" type="uint16">3</Field>





Even



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