diff options
| author | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2020-07-26 21:43:12 +0000 |
|---|---|---|
| committer | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2020-07-26 21:43:12 +0000 |
| commit | 1a29632fcc0b7c095f116ad9a760acc80a7b0472 (patch) | |
| tree | 17fec5ed1778a7b800faeb32a3efb0f3934ae98e /pnmtopng.html | |
| parent | fabc39e7f3bf78fbbc4e2923a0b9e53a829a9a26 (diff) | |
| download | netpbm-mirror-1a29632fcc0b7c095f116ad9a760acc80a7b0472.tar.gz netpbm-mirror-1a29632fcc0b7c095f116ad9a760acc80a7b0472.tar.xz netpbm-mirror-1a29632fcc0b7c095f116ad9a760acc80a7b0472.zip | |
miscellaneous update
git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@3901 9d0c8265-081b-0410-96cb-a4ca84ce46f8
Diffstat (limited to 'pnmtopng.html')
| -rw-r--r-- | pnmtopng.html | 190 |
1 files changed, 101 insertions, 89 deletions
diff --git a/pnmtopng.html b/pnmtopng.html index 167291aa..e2c3f9bd 100644 --- a/pnmtopng.html +++ b/pnmtopng.html @@ -1,18 +1,17 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN"> -<HTML> -<HEAD><TITLE>Pnmtopng User Manual</TITLE></HEAD> -<BODY> -<H1>pnmtopng</H1> +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.3//EN"> +<html><head><title>Pnmtopng User Manual</title></head> +<body> +<h1>pnmtopng</h1> Updated: 13 March 2019 -<BR> -<A HREF="#index">Table Of Contents</A> +<br> +<a href="#index">Table Of Contents</a> -<H2>NAME</H2> +<h2>NAME</h2> pnmtopng - convert a PNM image to PNG -<H2 id="synopsis">SYNOPSIS</H2> +<h2 id="synopsis">SYNOPSIS</h2> -<B>pnmtopng</B> +<b>pnmtopng</b> [<b>-verbose</b>] [<b>-downscale</b>] [<b>-interlace</b>] @@ -45,14 +44,14 @@ pnmtopng - convert a PNM image to PNG [<b>-comp_buffer_size=</b><i>n</i>] [<b>-force</b>] [<b>-libversion</b>] -[<I>pnmfile</I>] +[<i>pnmfile</i>] -<?makeman .SH OPTION USAGE ?> +<?makeman .sh option usage ?> <p> Obsolete options: <p> -[<b>-filter </b><I>n</I>] +[<b>-filter </b><i>n</i>] <p> Options available only in older versions: @@ -63,18 +62,18 @@ Options available only in older versions: [<b>-time </b>[<i>yy</i>]<i>yy</i><b>-</b><i>mm</i><b>-</b><i>dd</i> <i>hh</i><b>:</b><i>mm</i><b>:</b><i>ss</i>] -<P>Minimum unique abbreviation of option is acceptable. You may use double +<p>Minimum unique abbreviation of option is acceptable. You may use double hyphens instead of single hyphen to denote options. You may use white space in place of the equals sign to separate an option name from its value. -<H2 id="description">DESCRIPTION</H2> +<h2 id="description">DESCRIPTION</h2> <p>This program is part of <a href="index.html">Netpbm</a>. <p><b>pnmtopng</b> reads a PNM image as input and produces a PNG image as output. -<P>Color component values in PNG files are either eight or sixteen +<p>Color component values in PNG files are either eight or sixteen bits wide, so <b>pnmtopng</b> will automatically scale colors to have a maxval of 255 or 65535. @@ -98,7 +97,9 @@ power of two minus one (255 and 65535 are good choices) to minimize the error. -<H2 id="options">OPTIONS</H2> +<h2 id="options">OPTIONS</h2> + +<h3 id="notesyntax">Note: Option Syntax of Older Versions</h3> <p><b>pnmtopng</b> changed in Netpbm 10.30 (October 2005) to use the standard Netpbm command line syntax. Before that, you could not @@ -116,7 +117,7 @@ E.g. The old shell command <pre> <kbd> - pnmtopng -phys 800 800 0 input.pnm >output.png + pnmtopng -phys 800 800 0 input.pnm > output.png </kbd> </pre> @@ -124,28 +125,35 @@ E.g. The old shell command <pre> <kbd> - pnmtopng -size "800 800 0" input.pnm >output.png + pnmtopng -size "800 800 0" input.pnm > output.png </kbd> </pre> <p>If you're writing a program that needs to work with both new and old -<b>pnmtopng</b>, have it first try with the new syntax, and if it fails +, have it first try with the new syntax, and if it fails with "unrecognized option," fall back to the old syntax. -<DL COMPACT> -<DT><B>-verbose</B> -<DD> +<h3 id="curroptions">Current Options</h3> + +<p>In addition to the options common to all programs based on libnetpbm +(most notably <b>-quiet</b>, see <a href="index.html#commonoptions"> +Common Options</a>), <b>pnmtopng</b> recognizes the following +command line options: + +<dl compact> +<dt><b>-verbose</b> +<dd> This causes <b>pnmtopng</b> to display information about the format of the output file. -<DT><B>-downscale</B> -<DD> +<dt><b>-downscale</b> +<dd> This enables <b>pnmtopng</b> to scale maxvalues of more then 65535 to 16 bits. Since this means loss of image data, <b>pnmtopng</b> does not do it by default. -<DT><B>-interlace</B> -<DD> +<dt><b>-interlace</b> +<dd> This causes the PNG file to be interlaced, in Adam7 format. The interlaced format is one in which the raster data starts with a low-resolution representation of the entire image, then continues with additional information @@ -161,9 +169,9 @@ gradually paint down to the bottom. But with an interlaced image, the displayer can start by showing a low-resolution version of the image, then gradually improve the display as more data arrives. -<DT><B>-alpha=</b><i>filename</i> +<dt><b>-alpha=</b><i>filename</i> -<DD>This specifies the transparency (alpha) channel of the image. You supply +<dd>This specifies the transparency (alpha) channel of the image. You supply the transparency channel as a standard PGM transparency mask (see the <a href="pgm.html">PGM</a> specification. <b>pnmtopng</b> does not necessarily represents the transparency information as a transparency channel @@ -172,21 +180,21 @@ palette, it will do so in order to make a smaller PNG file. <b>pnmtopng</b> even sorts the palette so it can omit the opaque colors from the transparency part of the palette and save space for the palette. -<DT><B>-transparent=</b><i>color</i> -<DD> -<B>pnmtopng</B> marks the specified color as transparent in the PNG image. +<dt><b>-transparent=</b><i>color</i> +<dd> +<b>pnmtopng</b> marks the specified color as transparent in the PNG image. -<P>Specify the color (<i>color</i>) as described for the <a +<p>Specify the color (<i>color</i>) as described for the <a href="libnetpbm_image.html#colorname">argument of the <b>pnm_parsecolor()</b> library routine</a>. -E.g. <B>red</B> or -<B>rgb:ff/00/0d</B>. If the color you specify is not present in the -image, <B>pnmtopng</B> selects instead the color in the image that is +E.g. <b>red</b> or +<b>rgb:ff/00/0d</b>. If the color you specify is not present in the +image, <b>pnmtopng</b> selects instead the color in the image that is closest to the one you specify. Closeness is measured as a Cartesian distance between colors in RGB space. If multiple colors are -equidistant, <B>pnmtopng</B> chooses one of them arbitrarily. +equidistant, <b>pnmtopng</b> chooses one of them arbitrarily. -<P>However, if you prefix your color specification with +<p>However, if you prefix your color specification with "=", e.g. <pre> @@ -195,19 +203,19 @@ equidistant, <B>pnmtopng</B> chooses one of them arbitrarily. </kbd> </pre> -<P> only the exact color you specify will be transparent. If that +<p> only the exact color you specify will be transparent. If that color does not appear in the image, there will be no transparency. -<B>pnmtopng</B> issues an information message when this is the case. +<b>pnmtopng</b> issues an information message when this is the case. -<DT><B>-background=</b><i>color</i> -<DD> +<dt><b>-background=</b><i>color</i> +<dd> Causes <b>pnmtopng</b> to create a background color chunk in the PNG output which can be used for subsequent transparency channel or transparent color conversions. Specify <i>color</i> the same as for <b>-transparent</b>. -<DT><B>-palette=</b><i>palettefile</i> +<dt><b>-palette=</b><i>palettefile</i> -<DD>This option specifies a palette to use in the PNG. It forces +<dd>This option specifies a palette to use in the PNG. It forces <b>pnmtopng</b> to create the paletted (colormapped) variety of PNG -- if that isn't possible, <b>pnmtopng</b> fails. If the palette you specify doesn't contain exactly the colors in the image, @@ -217,10 +225,10 @@ only reason you would specify the <b>-palette</b> option is if you care in what order the colors appear in the palette. The PNG palette has colors in the same order as the palette you specify. -<P>You specify the palette by naming a PPM file that has one pixel for +<p>You specify the palette by naming a PPM file that has one pixel for each color in the palette. -<P>Alternatively, consider the case that have a palette and you want +<p>Alternatively, consider the case that have a palette and you want to make sure your PNG contains only colors from the palette, approximating if necessary. You don't care what indexes the PNG uses internally for the colors (i.e. the order of the PNG palette). In @@ -229,9 +237,9 @@ image and your palette PPM through <b>pnmremap</b>. Though you might think it would, using <b>-palette</b> in this case wouldn't even save <b>pnmtopng</b> any work. -<DT><B>-gamma=</b><i>value</i> +<dt><b>-gamma=</b><i>value</i> -<DD>Causes <b>pnmtopng</b> to create a gAMA chunk. This information helps +<dd>Causes <b>pnmtopng</b> to create a gAMA chunk. This information helps describe how the color values in the PNG must be interpreted. Without the gAMA chunk, whatever interprets the PNG must get this information separately (or just assume something standard). If your input is a true @@ -243,14 +251,14 @@ have digital computational ability. Also, some simple programs that generate images from scratch do it with a gamma transfer in which the gamma value is 1.0. -<DT><B>-hist</B> +<dt><b>-hist</b> -<DD>Use this parameter to create a chunk that specifies the frequency +<dd>Use this parameter to create a chunk that specifies the frequency (or histogram) of the colors in the image. -<DT><B>-text=</b><i>filename</i> +<dt><b>-text=</b><i>filename</i> -<DD> +<dd> This option lets you include arbitrary text strings in the PNG output, as tEXt chunks. @@ -286,9 +294,9 @@ delimiter characters after it, plus the text in subsequent continuation lines. <p>There is no limit on the length of a file line or entry or key or text string. There is no limit on the number of entries. -<DT><B>-ztxt=</b><i>filename</i> +<dt><b>-ztxt=</b><i>filename</i> -<DD>The same as <b>-text</b>, except the text string is compressed in the PNG +<dd>The same as <b>-text</b>, except the text string is compressed in the PNG output. <b>pnmtopng</b> uses zTXt chunks instead of a tEXt chunks, unless the key for the text string starts with "A" or "T". This odd exception exists for backward compatibility; we don't know why the program @@ -296,9 +304,9 @@ was originally designed this way, except that the distinction was meant to roughly identify the keys "Author" and "Title". -<DT><B>-rgb=</b><i>chroma_list</i> +<dt><b>-rgb=</b><i>chroma_list</i> -<DD>This option specifies how red, green, and blue component values +<dd>This option specifies how red, green, and blue component values of a pixel specify a particular color, by telling the chromaticities of those 3 primary illuminants and of white (i.e. full strength of all three). @@ -317,9 +325,9 @@ arguments. the option <b>-chroma</b> does the same thing, but with slightly different syntax. -<DT><B>-size="</b><i>x</i> <i>y</i> <i>unit</i><b>"</b> +<dt><b>-size="</b><i>x</i> <i>y</i> <i>unit</i><b>"</b> -<DD>This option determines the aspect ratio of the individual pixels +<dd>This option determines the aspect ratio of the individual pixels of your image as well as the physical resolution of it. <p><i>unit</i> is either <b>0</b> or <i>1</i>. When it is <i>1</i>, @@ -363,9 +371,9 @@ more information on what this really means. <p>This option was new in Netpbm 10.71 (June 2015). Before that, <b>pnmtopng</b> never generates an sRGB chunk. -<DT><B>-modtime="</b>[<i>yy</i>]<i>yy-mm-dd hh:mm:ss</i><b>"</b> +<dt><b>-modtime="</b>[<i>yy</i>]<i>yy-mm-dd hh:mm:ss</i><b>"</b> -<DD>This option allows you to specify the modification time value to +<dd>This option allows you to specify the modification time value to be placed in the PNG output. You can specify the year parameter either as a two digit or four digit value. @@ -373,9 +381,9 @@ either as a two digit or four digit value. the option <b>-time</b> does the same thing, but with slightly different syntax. -<DT><B>-filter=</b><i>n</i> +<dt><b>-filter=</b><i>n</i> -<DD>This option is obsolete. Before Netpbm 10.22 (April 2004), this was +<dd>This option is obsolete. Before Netpbm 10.22 (April 2004), this was the only way to specify a row filter. It specifies a single type of row filter, by number, that <b>pnmtopng</b> must use on each row. @@ -399,9 +407,9 @@ you could use the <b>-filter</b> option to specify one permitted row filter type. The default, when you specify no filter options, was the same. -<DT><B>-compression=</b><i>n</i> +<dt><b>-compression=</b><i>n</i> -<DD>This option sets set the compression level of the zlib +<dd>This option sets set the compression level of the zlib compression. Select a level from 0 for no compression (maximum speed) to 9 for maximum compression (minimum speed). @@ -437,7 +445,7 @@ library knows only one method today, so there's nothing to choose. <p>This option was new in Netpbm 10.30 (October 2005). -<dt><b>-comp_window_bits=</b><I>N</I> +<dt><b>-comp_window_bits=</b><i>N</i> <dd>This option tells how big a window the zlib compression algorithm uses. The value is the base 2 logarithm of the window size in bytes, @@ -450,7 +458,7 @@ to 32K). <p>This option was new in Netpbm 10.30 (October 2005). -<dt><b>-comp_buffer_size</b>=<I>N</I> +<dt><b>-comp_buffer_size</b>=<i>N</i> <dd>This option determines in what size pieces <b>pnmtopng</b> does the zlib compression. One compressed piece goes in each IDAT chunk in the @@ -466,9 +474,9 @@ compression buffer) in bytes. <p>This option was new in Netpbm 10.30 (October 2005). -<DT><B>-force</B> +<dt><b>-force</b> -<DD> +<dd> When you specify this, <b>pnmtopng</b> limits its optimizations. The resulting PNG output is as similar to the Netpbm input as possible. For example, the PNG output will not be paletted and the transparency channel will @@ -476,9 +484,9 @@ be represented as a full transparency channel even if the information could be represented more succinctly with a transparency chunk. -<DT><B>-libversion</B> +<dt><b>-libversion</b> -<DD> +<dd> This option causes <b>pnmtopng</b> to display version information about itself and the libraries it uses, <strong>in addition to all its normal function</strong>. Do not confuse this with the Netpbm common @@ -490,31 +498,35 @@ information about the Netpbm library and do nothing else. has changed too much over the history of <b>pnmtopng</b>. The option is good only for human eyes. -</DL> +</dl> -<H2 id="seealso">SEE ALSO</H2> +<h2 id="seealso">SEE ALSO</h2> -<A HREF="pngtopam.html">pngtopam</A>, -<A HREF="pamtopng.html">pamtopng</A>, -<A HREF="pnmremap.html">pnmremap</A>, -<A HREF="pnmgamma.html">pnmgamma</A>, -<A HREF="pnm.html">pnm</A> +<a href="pngtopam.html">pngtopam</a>, +<a href="pamtopng.html">pamtopng</a>, +<a href="pnmremap.html">pnmremap</a>, +<a href="pnmgamma.html">pnmgamma</a>, +<a href="pnm.html">pnm</a> <p>For information on the PNG format, see <a href="http://schaik.com/png">http://schaik.com/png</a>. -<H2 id="author">AUTHOR</H2> +<h2 id="author">AUTHOR</h2> Copyright (C) 1995-1997 by Alexander Lehmann and Willem van Schaik. -<HR> -<H2 id="index">Table Of Contents</H2> -<UL> -<LI><A HREF="#synopsis">SYNOPSIS</A> -<LI><A HREF="#description">DESCRIPTION</A> -<LI><A HREF="#options">OPTIONS</A> -<LI><A HREF="#seealso">SEE ALSO</A> -<LI><A HREF="#author">AUTHOR</A> -</UL> -</BODY> -</HTML> +<hr> +<h2 id="index">Table Of Contents</h2> +<ul> +<li><a href="#synopsis">SYNOPSIS</a> +<li><a href="#description">DESCRIPTION</a> +<li><a href="#options">OPTIONS</a> + <ul> + <li><a href="#notesyntax">Note: Option Syntax of Older Versions</a> + <li><a href="#curroptions">Current Options</a> + </ul> +<li><a href="#seealso">SEE ALSO</a> +<li><a href="#author">AUTHOR</a> +</ul> +</body> +</html> |