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diff --git a/directory.html b/directory.html index eb8ccd79..aefef595 100644 --- a/directory.html +++ b/directory.html @@ -575,7 +575,7 @@ convert JBIG BIE (compressed bitmap) to PNM <DT><B><a href=spottopgm.html>spottopgm</a></B> <DD>convert SPOT satellite image to PGM -<DT><B><a href=pamtoxvmini.html>pamtovmini</a></B> +<DT><B><a href=pamtoxvmini.html>pamtoxvmini</a></B> <DD>convert from Netpbm formats to Xv "thumbnail" picture <DT><B><a href=xvminitoppm.html>xvminitoppm</a></B> @@ -749,15 +749,6 @@ All of these generate Netpbm format output. <DT><B><a href=ppmrelief.html>ppmrelief</a> </B> <DD>run a Laplacian Relief filter on a PPM -<DT><B><a href=pamfunc.html>pamfunc</a></B> -<DD>apply simple arithmetic function to samples in an image - -<DT><B><a href=pamarith.html>pamarith</a> </B> -<DD>apply simple arithmetic binary function to samples in two images - -<DT><B><a href=pamsummcol.html>pamsummcol</a> </B> -<DD>summarize (sum, average, etc) an image by column - <DT><B><a href=pnmcat.html>pnmcat</a> </B> <DD>concatenate images @@ -798,13 +789,6 @@ All of these generate Netpbm format output. <DD>stitch together panoramic (side-by-side) photographs -<dt><b><a href="pnmmercator.html"></a></b> -<dd>Turns a rectangular projection map into a Mercator projection - -<DT><B><a href=ppmglobe.html>ppmglobe</a></b> - -<DD>Turn a cylindrical projection into strips that can be glued onto a sphere - <DT><B><a href=pamlookup.html>pamlookup</a></b> <DD>map an image to a new image by using it as indices into a table @@ -868,6 +852,9 @@ All of these generate Netpbm format output. <DT><B><a href=ppmchange.html>ppmchange</a> </B> <DD>change all of one color to another in PPM image +<DT><B><a href=pamrecolor.html>pamrecolor</a> </B> +<DD>alter colors without affecting luminance + <DT><B><a href=pnmnlfilt.html>pnmnlfilt</a></B> <DD>filter an image by replacing each pixel with a function of nearby pixels @@ -910,9 +897,25 @@ All of these generate Netpbm format output. <DT><B><a href=ppmdist.html>ppmdist</a> </B> <DD>map colors to high contrast grayscales arbitrarily +<dt><b><a href="pnmmercator.html"></a></b> +<dd>Turns a rectangular projection map into a Mercator projection + +<DT><B><a href=ppmglobe.html>ppmglobe</a></b> + +<DD>Turn a cylindrical projection into strips that can be glued onto a sphere + <DT><B><a href=ppmntsc.html>ppmntsc</a> </B> <DD>adjust colors so they are legal for NTSC or PAL television +<DT><B><a href=pamfunc.html>pamfunc</a></B> +<DD>apply simple arithmetic function to samples in an image + +<DT><B><a href=pamarith.html>pamarith</a> </B> +<DD>apply simple arithmetic binary function to samples in two images + +<DT><B><a href=pamsummcol.html>pamsummcol</a> </B> +<DD>summarize (sum, average, etc) an image by column + </DL> diff --git a/pamrecolor.html b/pamrecolor.html new file mode 100644 index 00000000..256280b7 --- /dev/null +++ b/pamrecolor.html @@ -0,0 +1,251 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> +<html> +<head> +<title>Pamrecolor User Manual</title> +<meta http-equiv="Content-type" content="text/html;charset=UTF-8"> +</head> + +<body> + +<h1>pamrecolor</h1> + +<p>Updated: 31 July 2010</p> + +<p><a href="#contents">Table Of Contents</a></p> + + +<h2 id="name">NAME</h2> + +<p>pamrecolor - alter colors without affecting luminance</p> + +<h2 id="synopsis">SYNOPSIS</h2> + +<p> +<b>pamrecolor</b> +[<b>--colorspace</b>=<i>name</i>] +[<b>--rmult</b>=<i>fraction</i>] +[<b>--gmult</b>=<i>fraction</i>] +[<b>--bmult</b>=<i>fraction</i>] +[<b>--targetcolor</b>=<i>color</i>] +[<b>--colorfile</b>=<i>file</i>] +[<i>infile</i>] +</p> + + +<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> + +<p>This program is part of <a href="index.html">Netpbm</a>.</p> + +<p><b>pamrecolor</b> changes an image's colors to be as close as +possible to given target colors but with the constraint that the +luminance not be modified. That is, the original image and the target +image will look identical if both are converted to grayscale +(e.g. with +<a href="ppmtopgm.html">ppmtopgm</a>). You can have <b>pamrecolor</b> select +target colors randomly, specify a single hue for the entire image, or take the +target colors from a target image.</p> + +<p><b>pamrecolor</b> works on pseudo-Netpbm images based on arbitrary +color spaces. You can define the color space explicitly or choose on +of many that <b>pamrecolor</b> knows by name. + +<p>The output is a PAM image on standard output. Options control the +exact format of the PAM. If you want a PNM (PBM, PGM, or PPM) image, +use <a href="pamtopnm.html">pamtopnm</a> on the output. There is no +need to convert if you will use the image as input to a current Netpbm +program, but many other programs don't know what a PAM is.</p> + + +<h2 id="options">OPTIONS</h2> + +<dl> + +<dt><b>--colorspace</b>=<i>name</i></dt> +<dd>Designate the color space to use for determining the contribution +to luminance of each of the red, green, and blue color channels. For +example, in the SMPTE-C color space an RGB color is converted to +grayscale by multiplying the red channel by 0.2124132, the green +channel by 0.7010437, and the blue channel by 0.0865432 and summing +the resulting three products. + +<p>When you use this option, the input and output images are not true Netpbm +images, because the Netpbm image format specifies a particular color space. +Instead, you are using a variation on the format in which the sample values in +the raster have different meaning. Many programs that ostensibly use Netpbm +images actually use a variation with a different color space, For example, +<a href="http://www.gimp.org/">GIMP</a> uses sRGB internally and if you +have GIMP generate a Netpbm image file, it really generates a variation of +the format that uses sRGB. + +<p><b>pamrecolor</b> knows the following color spaces (<i>name</i> values): + + <dl> + <dt>adobe</dt> + <dd>Adobe RGB (1998) with a D65 reference white</dd> + + <dt>apple</dt> + <dd>Apple RGB with a D65 reference white</dd> + + <dt>cie</dt> + <dd>CIE with an Illuminant E reference white</dd> + + <dt>ntsc</dt> + <dd>NTSC RGB with an Illuminant C reference white</dd> + + <dt>pal</dt> + <dd>PAL/SECAM with a D65 reference white</dd> + + <dt>smpte-c</dt> + <dd>SMPTE-C with a D65 reference white</dd> + + <dt>srgb</dt> + <dd>sRGB with a D65 reference white</dd> + + <dt>wide</dt> + <dd>Wide-gamut RGB with a D50 reference white</dd> + </dl> + +<p>The default is <q>ntsc</q> because this is the color space that the +Netpbm format +of Netpbm and many other graphics utilities. As a counterexample, +<a href="http://www.gimp.org/">GIMP</a> uses sRGB as its native color +space.</p> + +<p>The luminance values <b>pamrecolor</b> uses for each of the above come from +Bruce Lindbloom's +<a href="http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html"> +Computing RGB-to-XYZ and XYZ-to-RGB matrices</a> page.</p></dd> + +<dt><b>--rmult</b>=<i>fraction</i></dt> +<dt><b>--gmult</b>=<i>fraction</i></dt> +<dt><b>--bmult</b>=<i>fraction</i></dt> + +<dd>Instead of selecting a color space by name, you can specify explicitly the +contribution of each color channel to the overall luminance as red, green, and +blue multipliers. These three options must be used together, and the +three <i>fraction</i> values must sum to 1.0. For example, you can specify +the ProPhoto (ROMM) RGB color space with +<q><b>--rmult</b>=0.2880402 <b>--gmult</b>=0.7118741 <b>--bmult</b>=0.0000857</q>.</dd> + +<dt><b>--targetcolor</b>=<i>color</i></dt> +<dd>Designate <i>color</i> as the target color for the +image. <b>pamrecolor</b> will make each pixel as close as possible +to <i>color</i> subject to the constraint that the luminance must stay the +same as in the original image. Specify <i>color</i> as in +the <a href="libppm.html#colorname">argument of the <b>ppm_parsecolor()</b> +library routine</a> (e.g., <q>hotpink</q> or <q>#ff69b4</q>).</dd> + +<p>If you specify neither <b>--targetcolor</b> nor +<b>--colorfile</b>, <b>pamrecolor</b> will randomly select a target color for +each pixel of the input image.</p> + +<p>You may not specify both <b>-targetcolor</b> and <b>-colorfile</b>. + + +<dt><b>--colorfile</b>=<i>file</i></dt> +<dd>Take per-pixel target colors from Netpbm file <i>file</i> instead +of using a single target color for the entire image. +<i>file</i> should be a PPM or color PAM image. +If the image in the file wider or taller than the input image, +<b>pamrecolor</b> uses only the left and top part of it. +If the image is narrower or shorter, <b>pamrecolor</b> considers the +image to be repeated in a tile pattern. + +<p>If you specify neither <b>--targetcolor</b> nor +<b>--colorfile</b>, <b>pamrecolor</b> will randomly select a target color for +each pixel of the input image.</p> + +<p>You may not specify both <b>-targetcolor</b> and <b>-colorfile</b>. + +</dl> + + +<h2 id="examples">EXAMPLES</h2> + +<p>This command tints an image yellow:</p> + +<pre> + pamrecolor --targetcolor=yellow colorpic.pam > yellowpic.pam +</pre> + +<p>This command takes the colors from <b>colorpicture.ppm</b> and applies +them to <b>graypicture.pgm</b>:</p> + +<pre> + pamrecolor --colorfile=colorpic.ppm graypic.pgm > colorizedpic.pam +</pre> + +<p>The grayscale version of <b>colorizedpic.pam</b> will look just like +graypic.pgm. Note that if you use a non-Netpbm tool to do the conversion to +grayscale, you may additionally need to specify an +appropriate <b>--colorspace</b> value for your conversion tool.</p> + + +<h2 id="notes">NOTES</h2> + +<p>Here are a couple of fun special effects that can be produced using +<b>pamrecolor</b>:<p> + +<ol> +<li>Specify a color file that is identical to the input image but with +some large, colored text added to it. The text will <q>magically</q> +vanish when the image is converted to grayscale.</li> + +<li>Provide a low-contrast grayscale image — perhaps a secret +message written in similar shades of gray — as the input file and +a colorful but completely different image as the color file. If done +carefully, the grayscale image can be hidden by the colorful image. +Only people who know to convert the result to grayscale can recover +the original grayscale image.</li> + +<li>Use <b>--targetcolor</b>=tan to make an image look like an +old-timey photograph (or, more precisely, a +<a href="http://en.wikipedia.org/wiki/Photographic_print_toning">sepia-toned +photograph</a> of the late 1800s).</li> +</ol> + + +<h2 id="history">HISTORY</h2> + +<p>Scott Pakin wrote <b>pamrecolor</b> in July 2010.</p> + +<p><b>pamrecolor</b> was new in Netpbm 10.52 (September 2010). + + +<h2 id="author">AUTHOR</h2> + +<p>Copyright (C) 2010 Scott +Pakin, <a href="mailto:scott+pbm@pakin.org.">scott+pbm@pakin.org.</a></p> + + +<h2 id="seealso">SEE ALSO</h2> + +<ul> +<li><a href="ppmtopgm.html"><b>ppmtopgm</b></a> +<li><a href="ppmchange.html"><b>ppmchange</b></a> +<li><a href="pnmremap.html"><b>pnmremap</b></a> +</ul> + + +<hr> + +<h2 id="index">Table Of Contents</h2> + +<ul> +<li><a href="#synopsis">SYNOPSIS</a></li> +<li><a href="#description">DESCRIPTION</a></li> +<li><a href="#options">OPTIONS</a></li> +<li><a href="#examples">EXAMPLES</a></li> +<li><a href="#notes">NOTES</a></li> +<li><a href="#history">HISTORY</a></li> +<li><a href="#author">AUTHOR</a></li> +<li><a href="#seealso">SEE ALSO</a></li> +</ul> + +</body> +</html> + |