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.pdf > > 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 -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
