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nrrd

teem Riot-nrrd hackers unite
- Introduction
 
- File format
 
- Example NRRD files
 
- Compatible file formats
 
- Data structure
 
- Library description
 
- Example nrrd/unu uses
 
- Advocacy

Nearly Raw Raster Data

(no relationship to Norstan Inc., NASDAQ: NRRD)

Nrrd is a library and file format designed to support scientific visualization and image processing involving N-dimensional raster data. Nrrd stands for "nearly raw raster data". Besides dimensional generality, nrrd is flexible with respect to type (8 integral types, 2 floating point types), encoding of written files (raw, ascii, hex, or gzip or bzip2 compression), and endianness (the byte order of data is explicitly recorded when the type or encoding expose it). About two dozen operations are implemented, including simple things like quantizing, slicing, and cropping, and fancier things like projection, histogram equalization, and filtered resampling (up and down) with arbitrary seperable kernels.

This document aims to describe the NRRD file format and the nrrd library which can read and write NRRD files. Various examples illustrate the variety of possible nrrd operations available in the nrrd library, which are also accessible from the command-line "unu" program. Impatient readers should look at "Example NRRD files", "Examples of using nrrd", and "Advocacy".

In these pages, "NRRD" refers to the file format, "Nrrd" refers to the C struct defined in nrrd.h, "nrrd" refers to the library containing all the nrrd functions, , and "nrrd" is a general term for all of these.