[gdal-dev] Question about NITF CADRG data file extensions.

[Even Rouault]

Daniele,

From GDAL 1.5.0, there is a RPFTOC driver that can read the A.TOC file and 
reports a list of subdatasets. These subdatasets can then be opened with GDAL 
and they'll provide the list of frame files in metadata. See 
http://www.gdal.org/frmt_various.html#RPFTOC.

To answer exactly to your question, you can have a look at the 
frmts/nitf/nitffile.c file in the GDAL source tree, in particularly the 
array 'nitfSeries' at the end of the file. The first column gives the first 2 
letters of the possible extensions. If you add as the third character the 
figures from 1 to 9 (corresponding to the 9 ARC zones), you'll have all the 
possible extensions.  So you have .gn1 to .gn9, .on1 to .on9, .jn1 
to .jn9, .tp1 to .tp9, .jg1 to .jg9, .ja1 to .ja9, .tl1 to .tl9, etc... (from 
my experience, these are the extensions that'll cover 90% of the typical 
available CADRG products)


Le Tuesday 11 March 2008 17:10:39 Martin Chapman, vous avez écrit :
> Daniele,
>
>
>
> The RPF specification is MILSTD-2411 which has a couple of addendums and
> all can be found at http://earth-info.nga.mil/publications/specs/ .  The
> basic structure of an RPF file is a root directory named RPF which contains
> a file named a.toc which means "Table of Contents".  That file is a
> database of boundaries and frames files that make up the various images
> within the RPF file.  The boundaries constitute a group of adjacent frame
> files that together make a scene or image.  Each frame file is 1536 x 1536
> pixels and is formatted as an NITF file.  The frame files live within or
> below the RPF directory in other directories and the file name is a key
> that denotes the series, scale, zone and other information.  If you cannot
> open the frame files because your viewer wants an .ntf extension, just
> change the extension to .ntf and it will open in your viewer.  Then RPF is
> split into two types, Compressed Arc Digital Raster Graphics (CADRG) and
> Controlled Image Base (CIB).  The first is a vector map that has one band
> and a color table where the second is a one band gray scale image.  The
> main file you should be opening is always a.toc and then you should use the
> toc to retrieve whatever boundary and frame info you want.  The toc has the
> file paths for each of the frames files for a given boundary.
>
>
>
> Hope this helps!
>
>
>
> Best regards,
>
> Martin Chapman
>
>
>
> From: gdal-dev-bounces at lists.osgeo.org
> [mailto:gdal-dev-bounces at lists.osgeo.org] On Behalf Of Daniele Romagnoli
> Sent: Tuesday, March 11, 2008 8:55 AM
> To: gdal-dev at lists.osgeo.org
> Subject: [gdal-dev] Question about NITF CADRG data file extensions.
>
>
>
> Hi list,
> I have a trivial question about the supported/existing Nitf CADRG data file
> extensions.
>
> In the ImageIO-Ext project, I'm setting up a NITF plugin (leveraging on
> GDAL).
> The ImageReaderSpi of each ImageIO reader could specify the suffixes which
> the format specific plugin is able to support.
> Actually, I'm interested in CADRG format extensions. Thus, my silly
> question is:
> Which file extensions exist for the NITF CADRG format?
>
> After a "quick and random" search, I have found some ".on1", ".on2", ".on5"
> file extensions for Operational Navigation Chart and ".tp4" file extension
> for Tactical Pilotage Chart.
> I'm pretty sure there are ".onX" and ".tpX" (where X is a number) file
> extensions. Can someone give me some advice on this?
>
> Thank you very much.
>
> Best regards,
> Daniele