Read and write Netpbm files

Netpbmfile is a Python library to read and write image files in the Netpbm
or related formats:

PBM (Portable Bit Map): P1 (text) and P4 (binary)
PGM (Portable Gray Map): P2 (text) and P5 (binary)
PPM (Portable Pixel Map): P3 (text) and P6 (binary)
PNM (Portable Any Map): shorthand for PBM, PGM, and PPM collectively
PAM (Portable Arbitrary Map): P7, bilevel, gray, and rgb
PGX (Portable Graymap Signed): PG, signed grayscale
PFM (Portable Float Map): Pf (gray), PF (rgb), and PF4 (rgba), read-only
XV thumbnail: P7 332 (rgb332), read-only

The Netpbm formats are specified at https://netpbm.sourceforge.net/doc/.

The PGX format is specified in ITU-T Rec. T.803.

No gamma correction or scaling is performed.

:Author: Christoph Gohlke <https://www.cgohlke.com>_
:License: BSD-3-Clause
:Version: 2025.5.8

Quickstart

Install the netpbmfile package and all dependencies from the
Python Package Index <https://pypi.org/project/netpbmfile/>_::

python -m pip install -U "netpbmfile[all]"

See Examples_ for using the programming interface.

Source code and support are available on
GitHub <https://github.com/cgohlke/netpbmfile>_.

Requirements

This revision was tested with the following requirements and dependencies
(other versions may work):

CPython <https://www.python.org>_ 3.10.11, 3.11.9, 3.12.9, 3.13.2 64-bit
NumPy <https://pypi.org/project/numpy/>_ 2.2.5

Revisions

2025.5.8

Remove doctest command line option.

2025.1.1

Improve type hints.
Drop support for Python 3.9, support Python 3.13.

2024.5.24

Fix docstring examples not correctly rendered on GitHub.

2024.4.24

Support NumPy 2.

2023.8.30

Fix linting issues.
Add py.typed marker.

2023.6.15

Drop support for Python 3.8 and numpy < 1.21 (NEP29).
Improve type hints.

2023.1.1

Several breaking changes:
Rename magicnum to magicnumber (breaking).
Rename tupltypes to tupltype (breaking).
Change magicnumber and header properties to str (breaking).
Replace pam parameter with magicnumber (breaking).
Move byteorder parameter from NetpbmFile.asarray to NetpbmFile (breaking).
Fix shape and axes properties for multi-image files.
Add maxval and tupltype parameters to NetpbmFile.fromdata and imwrite.
Add option to write comment to PNM and PAM files.
Support writing PGX and text formats.
Add Google style docstrings.
Add unittests.

2022.10.25

…

Refer to the CHANGES file for older revisions.

Examples

Write a numpy array to a Netpbm file in grayscale binary format:

import numpy
data = numpy.array([[0, 1], [65534, 65535]], dtype=numpy.uint16)
imwrite('_tmp.pgm', data)

Read the image data from a Netpbm file as numpy array:

image = imread('_tmp.pgm')
numpy.testing.assert_equal(image, data)

Access meta and image data in a Netpbm file:

with NetpbmFile('_tmp.pgm') as pgm:
... pgm.magicnumber
... pgm.axes
... pgm.shape
... pgm.dtype
... pgm.maxval
... pgm.asarray().tolist()
...
'P5'
'YX'
(2, 2)
dtype('>u2')
65535
[[0, 1], [65534, 65535]]

View the image and metadata in the Netpbm file from the command line::

$ python -m netpbmfile _tmp.pgm

Dependencies of netpbmfile (3).
Dependency	Optional
numpy	false
matplotlib	true
tifffile	true

Package profile

netpbmfile

Releases

Release table

PyPI Downloads

Dependencies

Details

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Dependencies

Package description