NAME

       pamtowinicon - convert Netpbm PAM images to a Microsoft Windows icon file

SYNOPSIS

       pamtowinicon [-pngthreshold=threshold] [-truetransparent] [-verbose] [pam_file]

       All  options  can be abbreviated to their shortest unique prefix.  You may use two hyphens
       instead of one to designate an option.  You may use either white  space  or  equals  signs
       between an option name and its value.

DESCRIPTION

       This program is part of Netpbm(1).

       pamtowinicon  reads  an  RGB_ALPHA  Netpbm PAM file and converts it to a Microsoft Windows
       icon file.

       The output goes to Standard Output.

       The input is a multi-image PAM file; each image becomes an icon in the  output  file.   If
       you have input images in multiple files, you can simply combine them with cat and pass the
       result to pamtowinicon.

OPTIONS

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see  Common  Options  ⟨index.html#commonoptions⟩  ), pamtowinicon recognizes the following
       command line options:

       -pngthreshold=threshold
              pamtowinicon encodes images with resolutions above or equal threshold by  threshold
              as  PNG by running pnmtopng(1).  Other images it encodes using the more traditional
              BMP format.

              When the program uses PNG encoding for a 5-channel PAM with separate AND mask  (see
              below),  it  discards  the  AND  mask.   Because  PNG has always had the ability to
              specify transparency, the Windows icon format does not provide for a  separate  and
              mask when the icon is encoded in PNG.

              The default value for threshold is 128.

       -truetransparent
              Make all pixels outside the opaque area black, avoiding inversion and other effects
              on the background of the image (see Windows Icons(1)).

       -verbose
              Print more messages

IMAGES

       pamtowinicon reads a (multi-image) Netpbm PAM file as input and outputs an single  Windows
       icon file containing those images.

       The images in the icon file are in the same order as in the PAM input.

   PAM Input
       pamtowinicon interprets the PAM images as follows, based on the number of channels.

       ────────────────────────────────────────────────────────────────────
       channels   image
       1          fully opaque grayscale image
       2          grayscale image with transparency channel
       3          fully opaque color image
       4          color image with transparency channel
       5          color image with transparency channel and additional AND
       mask

       The tuple types of the PAMs are irrelevant.

   AND Mask
       The  so-called "AND mask" is a special feature of Microsoft Windows icons.  It is required
       for all BMP encoded images.  At the first sight, the AND  mask  is  a  1-bit  transparency
       channel,  but  it  is  also  used  for  e.g. shading the icon while dragging.  See Windows
       Icons(1) for details.

       If there is no explicit AND mask, but transparency data in the input  image,  pamtowinicon
       sets  the AND mask to opaque where the sample in the transparency channel is below maxval,
       and to transparent elsewhere.

       If no transparency data is present in the input  image,  pamtowinicon  assumes  the  whole
       image to be fully opaque.

   BMP Output
       When  BMP  encoding  an  image,  pamtowinicon  tries to use the most compact BI_RGB format
       allowed for icon images with a color depth of eight bits per channel.

       pamtowinicon generates neither 16-bit BI_RGB nor BI_BITFIELDS BMP encoded images, even  if
       the maxval of the input PAM is not 255.

SEE ALSO

       •

              winicontopam(1)

       •

              ppmtowinicon(1)

       •

              pam(1)

       •

              Windows Icons(1)

       For information on the PNG format, see http://schaik.com/png ⟨http://schaik.com/png⟩ .

HISTORY

       pamtowinicon  was new in Netpbm 10.63 (June 2013).  It obsoleted ppmtowinicon by providing
       more function and conforming better to Netpbm conventions.

AUTHOR

       Copyright (C) 2013 by Ludolf Holzheid.

       Translated to Netpbm coding style by Bryan Henderson.

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/pamtowinicon.html