                                   Tux Paint
                                 version 0.9.28
                               PNG Documentation

        Copyright © 2007-2022 by various contributors; see AUTHORS.txt.
                             https://tuxpaint.org/

                                  June 4, 2022

                                   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/.

   Proprietary Software for Windows
              * 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
