Nrrd

Nrrd ("nearly raw raster data") is a library and file format for the representation and processing of n-dimensional raster data. It was developed by Gordon Kindlmann^[1] to support scientific visualization and image processing applications.^[2]

nrrd
Filename extension	.nrrd
Type of format	Image file formats
Open format?	yes

Utah Nrrd Utilities

The command-line tool unu (Utah Nrrd Utilities) is used for the manipulation and management of nrrd files.^[2]

unu
Written in	C
Operating system	Cross-platform
Website	teem.sourceforge.net/unrrdu/index.html