PNG.txt for Tux Paint

Tux Paint - A simple drawing program for children.

Copyright 2002 by Bill Kendrick
bill@newbreedsoftware.com
http://www.newbreedsoftware.com/tuxpaint/

June 27, 2002 - November 7, 2002


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
  "paint brushes."


How To Make PNGs
----------------
  The following is a very _brief_ list of ways to create PNGs or
  convert existing images into PNGs.


  Linux/Unix Users
  ----------------
    The GIMP
    --------
      The best tool with which to create PNG images for use in Tux Paint is
      the GNU Image Manipulation Program ("The GIMP"), a high-quality
      Open Source interactive drawing and photo editing program.

      It's probably already installed on your Linux system.  If not, it's
      almost definitely available on the install CD or from your
      distribution's download site.  Otherwise:

        http://www.gimp.org/


    Krita
    -----
      Krita is a painting and image editing application for KOffice.

        http://koffice.kde.org/krita/


    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.

      NOTE: The NetPBM formats (Portable Bitmap: PBM,
      Portable Greymap: PGM, Portable Pixmap: PPM, and the catch-all
      Portable Any Map: PNM) do not support alpha, so any transparency
      information (e.g. from within a GIF) will be lost!  Use The GIMP!

      It's probably already installed on your Linux system.  If not, it's
      almost definitely available on the install CD or from your
      distribution's download site.  Otherwise:

        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's probably already installed on your Linux system.
      (Under Debian, this is available in the package "libjpeg-progs".)
      If not, it's almost definitely available on the install CD or from
      your distribution's download site.  Otherwise:

        ftp://ftp.uu.net/graphics/jpeg/


  Windows Users
  -------------
    The Gimp
      http://www.gimp.org/~tml/gimp/win32/

    Canvas (Deneba)
      http://www.deneba.com/products/canvas8/default2.html

    CorelDRAW (Corel)
      http://www.corel.com/

    Fireworks (Macromedia)
      http://macromedia.com/software/fireworks/
      
    Illustrator (Adobe)
      http://www.adobe.com/products/illustrator/main.html

    Paint Shop Pro (Jasc)
      http://www.jasc.com/products/psp/
    
    Photoshop (Adobe)
      http://www.adobe.com/products/photoshop/main.html


  Macintosh Users
  ---------------
    Canvas (Deneba)
      http://www.deneba.com/products/canvas8/default2.html

    CorelDRAW (Corel)
      http://www.corel.com/

    Fireworks (Macromedia)
      http://macromedia.com/software/fireworks/

    GraphicConverter (Lemke Software)
      http://www.lemkesoft.de/us_gcabout.html

    Illustrator (Adobe)
      http://www.adobe.com/products/illustrator/main.html
      
    Photoshop (Adobe)
      http://www.adobe.com/products/photoshop/main.html


More Info.
----------
  The libPNG website lists image editors and image converts that
  support the PNG format:

    http://www.libpng.org/pub/png/pngaped.html
    http://www.libpng.org/pub/png/pngapcv.html

