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diff --git a/pamsistoaglyph.html b/pamsistoaglyph.html index 84877178..1ca53ac8 100644 --- a/pamsistoaglyph.html +++ b/pamsistoaglyph.html @@ -1,23 +1,15 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN"> -<html xmlns="http://www.w3.org/1999/xhtml"> -<head> -<title>Pamsistoaglyph User Manual</title> -<meta http-equiv="content-type" content="text/html; charset=us-ascii" /> -</head> - +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.3//EN"> +<html><head><title>Pamsistoaglyph User Manual</title></head> <body> - <h1>pamsistoaglyph</h1> +Updated: 05 April 2009 +<br> +<a href="#index">Table Of Contents</a> -<p>Updated: 5 April 2009 - -<p><a href="#index">Table Of Contents</a></p> - +<h2>NAME</h2> -<h2 id="name">NAME</h2> - -<p>pamsistoaglyph - convert a single-image stereogram to a red/cyan -anaglyphic image</p> +pamsistoaglyph - convert a single-image stereogram to a red/cyan +anaglyphic image <h2 id="synopsis">SYNOPSIS</h2> @@ -28,11 +20,11 @@ anaglyphic image</p> [--<b>minsep</b>=<i>number</i>] [--<b>gray</b>=<i>number</i>] [<i>in_netpbmfile</i> -</p> + <p>All options can be abbreviated to their shortest unique prefix. You may use either white space or an equals sign between an option name -and its value.</p> +and its value. <h2 id="description">DESCRIPTION</h2> @@ -40,34 +32,38 @@ and its value.</p> <p>This program is part of <a href="index.html">Netpbm</a>. <p><b>pamsistoaglyph</b> reads a Netpbm image as input and -produces a Netpbm image as output.</p> +produces a Netpbm image as output. <p><b>pamsistoaglyph</b> takes a single-image stereogram (SIS) such as those produced by <a href= -"http://netpbm.sourceforge.net/doc/pamstereogram.html">pamstereogram</a> +"pamstereogram.html">pamstereogram</a> and converts it to a red/cyan anaglyphic image such as those produced -by <a href="http://netpbm.sourceforge.net/doc/ppm3d.html">ppm3d</a>. +by <a href="ppm3d.html">ppm3d</a>. Many people have trouble tricking their eyes into focusing beyond the image in front of them and are therefore unable to perceive the 3-D shape hidden within a single-image stereogram. Anaglyphic stereograms are easier to perceive in 3-D but require a pair of red/cyan glasses such as those often used to watch 3-D movies. The goal of <b>pamsistoaglyph</b> is to help people who have trouble -viewing single-image stereograms see the intriguing 3-D effect.</p> +viewing single-image stereograms see the intriguing 3-D effect. <p><b>pamsistoaglyph</b> can convert single-image random-dot stereograms (SIRDS), wallpaper stereograms, and even dual-image -stereograms to anaglyphic images.</p> +stereograms to anaglyphic images. <h2 id="options">OPTIONS</h2> -<p>For most images, no command-line options need to be specified. The -following options are available, however, for unusual -circumstances:</p> +<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>pamsistoaglyph</b> recognizes the following +command line options: + +<p>For most images, no command-line options need to be specified. The +following options are available, however, for unusual circumstances. <dl> -<dt><b>--invert</b></dt> +<dt><b>--invert</b> <dd>Swap the left- and right-eye images. <b>pamsistoaglyph</b> assumes that its input represents a wall-eyed stereogram and generates the anaglyphic @@ -75,17 +71,17 @@ circumstances:</p> the page where it should pop out of the page (and vice versa), this typically implies that the input image represents a cross-eyed stereogram. Use <b>--invert</b> to correct - the image depth.</dd> + the image depth. -<dt><b>--sep</b>=<i>number</i></dt> +<dt><b>--sep</b>=<i>number</i> <dd>Specify the distance in pixels between the left- and right-eye images. Essentially, this corresponds to the distance between repetitions of the background pattern. The <b>--sep</b> option should rarely be necessary as <b>pamsistoaglyph</b> is fairly good at determining - automatically the eye-separation distance.</dd> + automatically the eye-separation distance. -<dt><b>--minsep</b>=<i>number</i></dt> +<dt><b>--minsep</b>=<i>number</i> <dd>This option is similar to <b>--sep</b> but constrains <b>pamsistoaglyph</b> only to a <i>minimum</i> eye-separation distance. Any distance larger @@ -94,9 +90,9 @@ circumstances:</p> as <b>pamsistoaglyph</b> is fairly good at determining automatically the eye-separation distance. The default value for the minimum eye-separation distance is 10% of the image width; - this value seems to work well in practice.</dd> + this value seems to work well in practice. -<dt><b>--gray</b>=<i>number</i></dt> +<dt><b>--gray</b>=<i>number</i> <dd>Limit the number of gray levels to use when searching for the optimal eye-separation distance. Because <b>pamsistoaglyph</b> looks for @@ -107,7 +103,7 @@ circumstances:</p> unintentional color variations (such as those caused by conversion from a low-quality JPEG image, for example). The default of 63 seems to work well so the <b>--gray</b> option should - rarely be necessary.</dd> + rarely be necessary. </dl> @@ -116,22 +112,22 @@ circumstances:</p> <p>The registration algorithm used by <b>pamsistoaglyph</b> was developed specifically for this program. As far as the author knows, there are no existing algorithms for converting stereograms to -anaglyphs. The algorithm works as follows:</p> +anaglyphs. The algorithm works as follows: <ol> <li>Convert the image to grayscale to increase the ability to identify - matches.</li> + matches. <li>Count the number of pixels that match <i>N</i> pixels ahead in the - image for all <i>N</i> in [1, <i>width</i>/2].</li> + image for all <i>N</i> in [1, <i>width</i>/2]. <li>Maintain a running mean (μ) and standard deviation (σ) of - the number of matched pixels.</li> + the number of matched pixels. <li>Store the <i>N</i> corresponding to each spike in the number of matched pixels. A spike is defined as a tally that exceeds the mean plus one, two, or three standard deviations. Only the first - spike of a given standard-deviation multiplier is stored.</li> + spike of a given standard-deviation multiplier is stored. <li>If a tally greater than μ+3σ was encountered, return the corresponding <i>N</i>. If not, then if a tally greater than @@ -142,13 +138,13 @@ anaglyphs. The algorithm works as follows:</p> produces the minimum average distance between matched pixels (i.e., <i>#matches</i> divided by <i>#pixels</i>). If no such <i>N</i> exceeds the minimum allowable eye-separation value, - return zero to indicate failure.</li> + return zero to indicate failure. <li>If the algorithm returned zero, rerun the algorithm independently on each row of the input image and return the median of all <i>N</i> that exceed the minimum allowable eye-separation value. If no such <i>N</i> exists, abort with an error - message.</li> + message. </ol> <h2 id="history">HISTORY</h2> @@ -160,7 +156,7 @@ in Netpbm in Release 10.47 (June 2009). <h2 id="author">AUTHOR</h2> <p>Copyright (C) 2009 Scott -Pakin, <a href="mailto:scott+pbm@pakin.org.">scott+pbm@pakin.org.</a></p> +Pakin, <a href="mailto:scott+pbm@pakin.org.">scott+pbm@pakin.org.</a> <h2 id="seealso">SEE ALSO</h2> @@ -178,13 +174,13 @@ Pakin, <a href="mailto:scott+pbm@pakin.org.">scott+pbm@pakin.org.</a></p> <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="#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> +<li><a href="#synopsis">SYNOPSIS</a> +<li><a href="#description">DESCRIPTION</a> +<li><a href="#options">OPTIONS</a> +<li><a href="#notes">NOTES</a> +<li><a href="#history">HISTORY</a> +<li><a href="#author">AUTHOR</a> +<li><a href="#seealso">SEE ALSO</a> </ul> </body> |