pnmtopng(1)            AMIGA (27 May 1995)            pnmtopng(1)



     NAME
          pnmtopng - convert a portable anymap into a Portable Network
          Graphics file

     SYNOPSIS
          pnmtopng [-verbose] [-interlace] [-downscale] [pnmfile]

     DESCRIPTION
          Reads a portable pixmap as input.  Produces a Portable
          Network Graphics file as output.

          Color values in PNG files are either eight or sixteen bits
          wide, so pnmtopng will automatically scale colors to have a
          maxval of 255 or 65535.  Grayscale files will be produced
          with bit depths 1, 2, 4, 8 or 16.  An extra pnmdepth step is
          not necessary.

     OPTIONS
          -verbose
               Display the format of the output file.

          -interlace
               Creates an interlaced PNG file (Adam7).

          -downscale
               Enables scaling of maxvalues of more then 65535 to 16
               bit. Since this means loss of image data, the step is
               not performed by default.

          All flags can be abbreviated to their shortest unique
          prefix.

     SEE ALSO
          pngtopnm(1), gif2png(1), pnm(5)

     BUGS
          Due the fact that PNM files only include image data, it is
          not possible to preserve extra data (e.g. comments) stored
          with an image file. Instead of xxxtopnm|pnmtopng, a specific
          converter should be used, if available. E.g.  gif2png (GIF
          conversion), etc. (This is not really a bug in pnmtopng,
          more a general problem with intermediate formats.)

          Information about scaling is not preserved. No sBIT chunks
          are created.

     AUTHOR
          Copyright (C) 1995 by Alexander Lehmann, based on pnmtorast,
          (C) 1989,1990 by Jef Poskanzer.






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