pamtowinicon - convert Netpbm PAM images to a Microsoft Windows icon file
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.
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.
In addition to the options common to all programs based on libnetpbm (most
notably
-quiet, see
Common Options ),
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
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.
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.
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.
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.
- •
-
winicontopam(1)
- •
-
ppmtowinicon(1)
- •
-
pam(1)
- •
-
Windows Icons(1)
For information on the PNG format, see
http://schaik.com/png
.
pamtowinicon was new in Netpbm 10.63 (June 2013). It obsoleted
ppmtowinicon by providing more function and conforming better to Netpbm
conventions.
Copyright (C) 2013 by Ludolf Holzheid.
Translated to Netpbm coding style by Bryan Henderson.
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