[gdal-dev] JasPer vs OpenJPEG performance

[Even Rouault]

Le mardi 11 août 2015 07:59:09, Damian Bruce Leslie Dixon a écrit :
> Hi,
> 
> Even's interpretation of the NITF/NSIF standard is correct.
> 
> My experience is that Jasper reads all NITF test images so does Kakadu.
> 
> Kakadu is very fast however I've had problems with too many threads being
> used affecting overall system performance.

This can be controlled with the JP2KAK_THREADS env variable.

> 
> I've not tried openjpeg for a couple of years now... I'm hoping it has
> improved. When I tried it last there were problems reading the test
> images, some of which are badly formed on purpose.

I think I've read in one of their changelogs, probably openjpeg v2.1, that 
they made fixes to pass some compliance test suites.

> 
> Jasper is slow but does not have problems reading the test images.
> 
> Regards Damian
> 
> 
> 
> On 10 August 2015, at 2:34 pm, Even Rouault <even.rouault at spatialys.com>
> wrote:
> 
> Le lundi 10 août 2015 14:58:59, Jukka Rahkonen a écrit :
> > Brad Hards <bradh <at> frogmouth.net> writes:
> > > On Fri, 7 Aug 2015 11:17:56 AM Jukka Rahkonen wrote:
> > > > NITF requires either that the tile size must not be
> > > > bigger that 1024x1024, or that the whole file is written as one
> > > > single tile. I believe you have such single-tile NITF file.
> > > 
> > > I don't believe this is true (at least in NITF 2.1 - MIL-STD-2500C) for
> > > two reasons:
> > > 1. Tiling is mandatory above 8192 x 8192 (See Table A-10 Complexity
> > > Level
> > 
> > 7 or
> > 
> > > higher)
> > > 2. Tiles are allowed to be up to 2048 x 2048 (Complexity level 3) or
> > > 8192 x 8192 (Complexity level 5 or higher).
> > 
> > Hi Brad,
> > 
> > I read the NITF 2.1 - MIL-STD-2500C
> > http://www.gwg.nga.mil/ntb/baseline/docs/2500c/2500C.pdf in the same way
> > than you do. However, I wrote my comments after reading another (older)
> > document:
> > "NATIONAL IMAGERY TRANSMISSION FORMAT (NITF) VERSION 2.1 COMMERCIAL
> > DATASET REQUIREMENTS DOCUMENT (NCDRD)"
> > http://www.gwg.nga.mil/ntb/baseline/docs/stdi0006/NCDRD_18February2010.pd
> > f
> > 
> > And especially part
> > 2.3.2	JPEG 2000 Image Geometry Segmentation
> > Commercial datasets shall be organized in JPEG 2000 tiles as described in
> > BPJ2K01.00 Section 8.
> > 
> > I believe that the referred document is this:
> > http://www.gwg.nga.mil/ntb/baseline/docs/bpj2k01/ISOJ2K_profile.pdf
> > 
> > Appendix C  JPEG 2000 Commercial Profiles (ISO/IEC IS 15444-1
> > Annex A.10)  , Table C-1. Codestream Restrictions:
> > 
> > Profile-0:
> > Tiles of a dimension 128x128:
> > YTsiz=XTsiz=128
> > or one tile for the whole
> > image:
> > YTsiz+YTOsiz>=Ysiz
> > XTsiz+XTOsiz>=Xsiz
> > 
> > Profile-1
> > XTsiz/min(XRsiz, YRsiz)<=1024
> > XTsiz=YTsiz
> > 
> >  or one tile for the whole image:
> > YTsiz+YTOsiz>=Ysiz
> > XTsiz+XTOsiz>=Xsiz
> > 
> > 
> > It may be that tiling is mandatory for images bigger than 8192 x 8192
> > because of the baseline standard. On the other hand is seems that
> > commercial vendors are not allowed to use multiple tiles if they are
> > larger than 1024 x 1024. I did not dig too deep into the black hole
> > between 1024 x 1024 and 8192 x 8192.
> 
> Nice hunt through standards ;-)
> 
> If the image is tiled, no issue.
> 
> Found in the documents you mentionned :
> - http://www.gwg.nga.mil/ntb/baseline/docs/bpj2k01/ISOJ2K_profile.pdf at
> paragraph 9.2.1.2 Tiling "It is recommended that the image be tiled with
> in a JPEG 2000 codestream."
> - http://www.gwg.nga.mil/ntb/baseline/docs/bpj2k01/ISOJ2K_profile.pdf at
> paragraph 8.1 "The following JPEG 2000 parameter choices are recommended
> [...] Images are tiled with JPEG 2000 at a tile size of 1024x1024"
> 
> So I think that the single-tile scheme that is theoretically possible by
> the Profile-1 of the JPEG2000 standard is not to be used in JPEG2000
> compressed NITF.
> 
> Looking at a NITF sample from a commercial provider, I can see it uses
> 1024x1024 tiles for example.
> 
> Even

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