PNM Files

PNM is a data directory which contains examples of PNM files. "PNM" stands for "Portable Any Map" and is intended to cover all six variations of Jef Poskanzer's portable bit/gray/pixel maps, (PBM, PGM, and PPM) whether ASCII or binary.

PNM File Characteristics:

• ASCII (P1, P2, P3) or binary (P4, P5, P6)
• B/W (P1 or P4), Gray (P2 or P5), or Color (P3 or P6)
• 2D
• No compression
• 1 image

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Related Data and Programs:

The PBMA data directory describes the ASCII Portable Bit Map format.

The PBMB data directory describes the binary Portable Bit Map format.

The PGMA data directory describes the ASCII Portable Gray Map format.

The PGMB data directory describes the binary Portable Gray Map format.

The PPMA data directory describes the ASCII Portable Pixel Map format.

The PPMB data directory describes the binary Portable Pixel Map format.

Reference:

1. the NETPBM homepage.

Programs and routines to read a PNM file:

• MATLAB can read a PNM file with a command like A=imread('file','PNM').

Programs and routines to write a PNM file:

• MATHEMATICA includes an Export[filename,object] command that can save a graphics object as a PNM file.
• MATLAB can write a PNM file with a command like imwrite(a,'filename','PNM').

Programs to display a PNM file include:

• The AVS module read_any_image can display a PNM file.
• GIMP, the GNU Image Manipulation Program, can display a PNM file.
• xv can display a PNM file.

Programs to convert a PNM file to another format:

• The ImageMagick, program convert can convert a PNM file to BMP, CGM, EPS, FIG, FITS, GIF, JPG, PBM, PDF, PGM, PNG, PPM, PS, RGB, TIF, XBM or XPM format.
• GIMP, the GNU Image Manipulation Program, can read a PNM file and write out a copy in a variety of formats.
• The NETPBM program pnmtopng can convert a PNM file to a PNG file.
• The Visualization Toolkit routine vtkPNMReader can read a PNM file into VTK.

Programs to convert a file to PNM format:

• The ImageMagick, program convert can convert a BMP, CGM, EPS, FIG, FITS, GIF, JPG, PBM, PDF, PGM, PNG, PPM, PS, RGB, TIF, XBM or XPM file to PNM format.
• the program giftopnm can convert a GIF file to a PNM file.
• GIMP, the GNU Image Manipulation Program, can read a file in a variety of formats, and write it out as a PNM file.
• The NETPBM program jpegtopnm can convert a JPEG file to a PNM file.
• The NETPBM program pngtopnm can convert a PNG file to a PNM file.
• The Visualization Toolkit routine vtkPNMWriter can write a VTK image to a PNM file.
• xv can save a PNM file as a BMP, FITS, GIF, JPEG, PS, RGB, or TIFF.

Sample PNM Files:

• circle.pnm, a circle, type P1 (a PBMA file);
• circle2.pnm, a circle, type P4 (a PBMB file);
• rays.pnm, a pattern of rays, type P2 (a PGMA file);
• rays2.pnm, a pattern of rays, type P5 (a PGMB file);
• snail.pnm, a snail, type P3 (a PPMA file);
• snail2.pnm, a snail, type P6 (a PPMB file);

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