.. index:: PNG (Portable Network Graphics)
.. index:: .png

PNG (Portable Network Graphics)
===============================================================================

Extensions: .png

Developer: `PNG Development Group <http://www.libpng.org/pub/png/pngnews.html>`_


**Support**


BSD-licensed: |yes|

Export: |yes|

Officially Supported Versions: 

Reader: APNGReader (:bsd-reader:`Source Code <APNGReader.java>`, :doc:`Supported Metadata Fields </metadata/APNGReader>`)

Writer: APNGWriter (:bsd-writer:`Source Code <APNGWriter.java>`)

Freely Available Software:

- `PNG Writer plugin for ImageJ <https://imagej.net/ij/plugins/png-writer.html>`_


We currently have:

* a `PNG specification document <http://www.libpng.org/pub/png/spec/iso/>`_ (W3C/ISO/IEC version, from 2003 November 10, in HTML) 
* several PNG datasets
* `public sample images <https://downloads.openmicroscopy.org/images/PNG/>`__



**Ratings**


Pixels: |Very good|

Metadata: |Very good|

Openness: |Outstanding|

Presence: |Outstanding|

Utility: |Poor|

**Additional Information**


Bio-Formats uses the `Java Image I/O <https://docs.oracle.com/javase/7/docs/technotes/guides/imageio/>`_  
API to read and write PNG files. 

.. seealso:: 
  `PNG technical overview <http://www.libpng.org/pub/png/>`_
