netpbmfile 2020.10.18

Read and write Netpbm files

Netpbmfile is a Python library to read and write image files in the Netpbm format as specified at http://netpbm.sourceforge.net/doc/.

The following Netpbm and Portable FloatMap formats are supported:

• PBM (bi-level)
• PGM (grayscale)
• PPM (color)
• PAM (arbitrary)
• XV thumbnail (RGB332, read-only)
• PF (float32 RGB, read-only)
• Pf (float32 grayscale, read-only)

No gamma correction is performed. Only one image per file is supported.

Author:	Christoph Gohlke
Organization:	Laboratory for Fluorescence Dynamics, University of California, Irvine
License:	BSD 3-Clause
Version:	2020.10.18

Requirements

• CPython >= 3.7
• Numpy 1.15
• Matplotlib 3.2 (optional for plotting)

Revisions

2020.10.18

Disallow comments after last value in PNM headers.

2020.9.18

Remove support for Python 3.6 (NEP 29). Support os.PathLike file names.

2020.1.1

Fix reading tightly packed P1 format and ASCII data with inline comments. Remove support for Python 2.7 and 3.5. Update copyright.

2018.10.18

Move netpbmfile.py into netpbmfile package.

2018.02.18

Support Portable FloatMaps. Style fixes.

2016.02.24

Use ‘fromdata’ classmethod to initialize from data. Support ‘with’ statement. Scale RGB images to maxval for display. Make keyword arguments explicit. Support numpy 1.10.

Examples

Save a numpy array to a Netpbm file in grayscale format:

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

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

>>> image = imread('_tmp.pgm')
>>> assert numpy.all(image == data)

Access meta and image data in a Netpbm file:

>>> with NetpbmFile('_tmp.pgm') as pgm:
...     pgm.axes
...     pgm.shape
...     pgm.dtype
...     pgm.maxval
...     pgm.magicnum
...     image = pgm.asarray()
'YX'
(2, 2)
dtype('>u2')
65535
b'P5'