NITF -- National Imagery Transmission Format

GDAL supports reading of several subtypes of NITF image files, and writing simple NITF 2.1 files. NITF 1.1, NITF 2.0, NITF 2.1 and NSIF 1.0 files with uncompressed, ARIDPCM, JPEG compressed, JPEG2000 (with Kakadu, ECW SDKs or other JPEG2000 capable driver) or VQ compressed images should be readable.

The read support test has been tested on various products, including CIB and CADRG frames from RPF products, ECRG frames, HRE products.

Color tables for pseudocolored images are read. In some cases nodata values may be identified.

Lat/Long extents are read from the IGEOLO information in the image header if available. If high precision lat/long georeferencing information is available in RPF auxiliary data it will be used in preference to the low precision IGEOLO information. In case a BLOCKA instance is found, the higher precision coordinates of BLOCKA are used if the block data covers the complete image - that is the L_LINES field with the row count for that block is equal to the row count of the image. Additionally, all BLOCKA instances are returned as metadata. If GeoSDE TRE are available, they will be used to provide higher precision coordinates.

Most file header and image header fields are returned as dataset level metadata.

Creation Issues

On export NITF files are always written as NITF 2.1 with one image and no other auxiliary layers. Images are uncompressed by default, but JPEG and JPEG2000 compression are also available. Georeferencing can only be written for images using a geographic coordinate system or a UTM WGS84 projection. Coordinates are implicitly treated as WGS84 even if they are actually in a different geographic coordinate system. Pseudo-color tables may be written for 8bit images.

In addition to the export oriented CreateCopy() API, it is also possible to create a blank NITF file using Create() and write imagery on demand. However, using this methology writing of pseudocolor tables and georeferencing is not supported unless appropriate IREP and ICORDS creation options are supplied.

Creation Options:



The author wishes to thank AUG Signals and the GeoConnections program for supporting development of this driver, and to thank Steve Rawlinson (JPEG), Reiner Beck (BLOCKA) for assistance adding features.