View source for Netpbm formats

{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|pbm}}, {{ext|pgm}}, {{ext|ppm}}, {{ext|pnm}}
|pronom={{PRONOM|fmt/408}}, others
|released=1988
}}
The '''Netpbm formats''' are a family of simple raster image file formats, associated with the [[Netpbm]] library and suite of image processing utilities.

== Formats ==
* '''PBM''' (portable bitmap) is a bi-level image format.
* '''PGM''' (portable graymap) is a grayscale image format.
* '''PPM''' (portable pixmap) is a color image format.
* '''PNM''' (portable anymap) is a collective name for PBM, PGM, and PPM. A .pnm file may use any of those formats.
* '''PAM''': Refer to [[PAM (Portable Arbitrary Map)]]. Although PAM is one of the Netpbm formats, it's different enough that it's best documented in a separate article.

== Identification ==
Each file begins with two ASCII characters, which serve as a signature.

The PBM, PGM, and PPM formats come in two varieties: a text ("plain") format, and a binary ("raw") format.

{| class="wikitable"
! Format
! Signature
! PRONOM
|-
|PBM, text || <code>P1</code> || {{PRONOM|x-fmt/164}}
|-
|PGM, text || <code>P2</code> || {{PRONOM|fmt/407}}
|-
|PPM, text || <code>P3</code> || {{PRONOM|x-fmt/178}}
|-
|PBM, binary || <code>P4</code> || {{PRONOM|fmt/409}}
|-
|PGM, binary || <code>P5</code> || {{PRONOM|fmt/406}}
|-
|PPM, binary ||  <code>P6</code> || {{PRONOM|fmt/408}}
|}

== See also ==
* [[PAM (Portable Arbitrary Map)]]
* [[PFM (Portable Float Map)]]

== Specifications ==
* [http://netpbm.sourceforge.net/doc/pbm.html PBM Format Specification]
* [http://netpbm.sourceforge.net/doc/pgm.html PGM Format Specification]
* [http://netpbm.sourceforge.net/doc/ppm.html PPM Format Specification]

== Software ==
* [[Netpbm]]

== External links ==
* [[Wikipedia:Netpbm format|Wikipedia: Netpbm format]]