PNM (.pnm)

Background & Context

    • MIME types: image/x-portable-anymap, image/pbm
    • PNM raster image format.
    • Generic format of the Portable family of image formats.
    • Includes the PBM (monochrome), PGM (gray-level), and PPM (RGB color) image formats.
    • Native format of the Netpbm graphics software package.
    • Primarily used as an intermediate file format on Unix systems.
    • PNM is an acronym derived from Portable Any Map.
    • ASCII or binary format.
    • Stores raster images formatted as plain text, representing each pixel as a color value.

Import & Export

  • Import["file.pnm"] imports a PNM file, returning an Image object.
  • Import["file.pnm",elem] imports the specified element from a PNM file.
  • The import format can be specified with Import["file","PNM"] or Import["file",{"PNM",elem,}].
  • Export["file.pnm",expr] exports an image, graphics, or any other expression as a raster image to PNM.
  • Export by default generates binary PNM files.
  • When exporting Wolfram Language graphics or arbitrary expressions to PNM, the resulting image has the same raster size as its displayed form.
  • Image objects are by default exported at their raster size.
  • Because PNM is a raster image format, all fonts are rasterized on export.
  • See the following reference pages for full general information:
  • Import, Exportimport from or export to a file
    CloudImport, CloudExportimport from or export to a cloud object
    ImportString, ExportStringimport from or export to a string
    ImportByteArray, ExportByteArrayimport from or export to a byte array

Notebook Interface

  • In the notebook front end, Insert Picture and the Open menu allow import of a PNM file into a cell.
  • Save Selection As exports the selected part of a notebook as a PNM file.

Import Elements

  • General Import elements:
  • "Elements" list of elements and options available in this file
    "Summary"summary of the file
    "Rules"list of rules for all available elements
  • Data representation elements:
  • "Data"array of color values
    "Graphics"Graphics object representing an image
    "Image"raster image, given as an Image object
  • Import by default uses "Image" for single-frame PNM files and "ImageList" for multi-frame PNM files.
  • Advanced Import elements:
  • "BitDepth"bits used to represent each color channel in the file
    "Channels"the number of color channels used in the file
    "ColorSpace"color space of the image
    "DataType"data type used for storing pixel elements
    "ImageSize"raster dimensions
    "Summary"summary of the file



Basic Examples  (3)

Import a PNM file:

Summary of an image:

Export an image object to PNM: