                                   Tux Paint
                                 version 0.9.26
                               PNG Documentation

          Copyright © 2007-2021 by various contributors; see AUTHORS.
                            http://www.tuxpaint.org/

                                 March 9, 2021

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About PNGs

   PNG is the Portable Network Graphic format. It is an open standard, not
   burdened by patents (like GIFs). It is a highly compressed format (though
   not "lossy" like JPEGs - lossiness allows files to be much smaller, but
   introduces 'mistakes' in the image when saved), and supports 24-bit color
   (16.7 million colors) as well as a full "alpha channel" - that is, each
   pixel can have a varying degree of transparency.

   For more information, visit: http://www.libpng.org/

   These features (openness, losslessness, compression, transparency/alpha)
   make it the best choice for Tux Paint. (Tux Paint's support for the PNG
   format comes from the Open Source SDL_Image library, which in turn gets it
   from the libPNG library.)

   Support for many colors allows photo-quality "rubber stamp" images to be
   used in Tux Paint, and alpha transparency allows for high-quality brushes.

How To Make PNGs

   The following is a very brief list of ways to create PNGs or convert
   existing images into PNGs.

  GIMP & Krita

   Excellent tools with which to create PNG images for use in Tux Paint are
   GIMP and Krita, both high-quality Open Source interactive drawing and
   photo editing programs.

   It is likely that one or both are already installed on your system. If
   not, they should be readily available from your Linux distribution's
   software repository. If not, or to learn more, visit http://www.gimp.org/
   and http://www.krita.org/, respectively.

  Command-line Tools

    NetPBM

   The Portable Bitmap tools (collectively known as "NetPBM") is a collection
   of Open Source command-line tools which convert to and from various
   formats, including GIF, TIFF, BMP, PNG, and many more.

   It is possible that it's already installed on your system. If not, they it
   be readily available from your Linux distribution's software repository.
   If not, or to learn more, visit http://netpbm.sourceforge.net/.

    cjpeg/djpeg

   The "cjpeg" and "djpeg" command-line programs convert between the NetPBM
   Portable Any Map (PNM) format and JPEGs. It is possible that it's already
   installed on your system. If not, they it be readily available from your
   Linux distribution's software repository. If not, or to learn more, visit
   https://jpegclub.org/.

  Windows Users

     * CorelDRAW (Corel) — http://www.corel.com/
     * Illustrator (Adobe) — http://www.adobe.com/products/illustrator.html
     * Paint Shop Pro (Corel) — https://www.paintshoppro.com/
     * Photoshop (Adobe) — http://www.adobe.com/products/photoshop.html
     * PIXresizer (Bluefive software) —
       http://bluefive.pair.com/pixresizer.htm

  Macintosh Users

     * CorelDRAW (Corel) — http://www.corel.com/
     * GraphicConverter (Lemke Software) —
       https://www.lemkesoft.de/mac-fotobearbeitung-mac-diashow-mac-grafikprogramm-mac-bildbetrachter/
     * Illustrator (Adobe) — http://www.adobe.com/products/illustrator.html
     * Photoshop (Adobe) — http://www.adobe.com/products/photoshop.html
