Pamtowinicon User Manual(0) Pamtowinicon User Manual(0)NAMEpamtowinicon - convert Netpbm PAM images to a Microsoft Windows icon
file
SYNOPSISpamtowinicon [-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 sim‐
ply 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) using the
more traditional BMP format.
When the program uses PNG encoding for a 5-channel PAM with sep‐
arate AND mask (see below), it discards the AND mask.
The default value for threshold is 128.
-truetransparent
Make all pixels outside the opaque area black, avoiding inver‐
sion and other effects on the background of the image (see Win‐
dowsIcons(1) ).
-verbose
Print more messages
IMAGESpamtowinicon 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.
<TABLE summary="Image type based on number of channels" border=1
align="center"> <TR><TH>channels</TH><TH>image</TH></TR>
<TR><TD>1</TD><TD>fully opaque grayscale image</TD></TR>
<TR><TD>2</TD><TD>grayscale image with alpha channel</TD></TR>
<TR><TD>3</TD><TD>fully opaque color image</TD></TR>
<TR><TD>4</TD><TD>color image with alpha channel</TD></TR>
<TR><TD>5</TD><TD>color image with alpha channel and additional AND
mask</TD></TR> </TABLE>
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 alpha channel, but it is also used
for e.g. shading the icon while dragging. See WindowsIcons(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
alpha 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(5)
·
WindowsIcons(1)
For information on the PNG format, see http://schaik.com/png
⟨http://schaik.com/png⟩ .
HISTORYpamtowinicon was new in Netpbm 10.63 (June 2013). It obsoleted ppm‐
towinicon 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.
netpbm documentation 12 April 2013 Pamtowinicon User Manual(0)
